Interior Design (Principles& Practice)

PREFACE Interior design is a fast developing discipline. Its importance lies in the fact that the interior use of an en...

Author: Partap Rao M.

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PREFACE Interior design is a fast developing discipline. Its importance lies in the fact that the interior use of an enclosed space is changing frequently due to the. fast changing life styles. What we need today is an' enclosed. space which can adopt to these fast changing needs. ~ Thus tl1eneed of an mterior Designer will increase in the coming years. . " In India" we are.slowly accepting this fact. In the process, many schools of interior desig-nare started offering dip mas an
~.'

~

- Most of the students nf interior desigfl are not very clear about the syllabus and method of study. They are attracted to the profession for the glamour and glossy photographs in magazines. There is no real 'textbook' which can guide the students of intenor design, and this

book tries to meet that desperate need.

I

This book is divided into two sections as Theory and Drawing. The theory part contains History of interior design, Basics of design composition, Introduction to building materials, Plumbing, Natural ventilation, Air-conditioning, Natural & Artificial lighting, Acoustics, Building protection, Interior furnishing and information on Indian Institute of Interior Designers. The drawing part contains Lettering & Scales, Figures & Projections, Building material symbols, Space standards, External & Internal parts, Kitchen design, Staircases, Theory of colours, Rendering techniques, Three dimensional views and Interior design method. These are the most essential topics and drawing exercises a student of interior design should learn. I tried to incorporate the latest information available on each subject suiting to Indian conditions. I would have included many other topics, but then, it would. become an encyclopedia than a textbook for easy reading and understanding. However, I welcome suggestions to improve the text in the coming editions from the students and fellow professi~nals in \

interior design.

M. PRATAP RAO

CONTENTS THEORY ! CHAPTER 1. IDSTORY OF INTERIOR DESIGN . I. Interior decoration as a profession, I 2. Emergence of professional interior designer, I .

3. Modem interior design features, I CHAPTER 2. BASICS OF DESIGN COMPOSITION. . I 1. The elements, 3 2. The principles,. 3 3. Golden mean rectangle, 6. CHAPTER

3. INTRODUCTION

TO BUILDING

1. Stone, 7 2. Clay products, 9 3. Cement. 10 4. Mortar, to 5. Concrete, 10 6. TImber, II 7. Plywood and related products, II 8. Plastics and related products, 12 9. Glass and related products, 12 10. Paints and related products, 13 11. Ferrous and Non-ferrous metals, 13 12. Gypsum and related products, 14 13. Adhesives (or Glues), 14 CHAPTER 4. PLUMBING 1. Water Supply, 15

2. Sanitation,17

MATERIALS .

2. 3. 4. 5.

Atmospheric conditions for human comfort, 29 Process of air-conditioning, 30 Air-conditioning under lndianclimatic conditions, 30 Types of Air-conditioning methods, 30

6. Refrigeration methods, 32

.

7. Calculation of packaged systems, 32 .

CHAPTER 7. NATURAL LIGHTING. 1. Daylight factor, 33 2. Recommended daylight factors for interiors, 33 3. Calculation of the openings for natural lighting, 34 4. Guidelines for good natural lighting, 36 CHAPTER 8. ARTIFICIAL LIGHTING 1. Different types of lighting arrangements, 38 2. Variety of lamps, 39 3. Lighting accessories, 41 4. Protection devices, 44 5. Calculation of artificial lighting requirement, 45 6. Electrical wiring, 47 CHAPTER 9. ACOUSTICS I. Properties of sound, 50 2. Sound in interiors, 52 3. Sound absorption, 53 4. Acoustic design of a hall, 55 5. Guidelines for good acoustic design, 56 CHAPTER 10. BUILDING PROTECTION 1. Dampness Protection, 57 2. Tcrmite Protectio~, 60 3. Fire Protection, 61 CHAPTER 11. INTERIOR FURNISHING 1. Ceiling, 63 2. Walls, 64 3. Doors and Windows, 65 4. Flooring, 65 5. Furniture, 68 6. Decorative items, 68 CHAPTER 12. PAINTING INTERIORS J. Ingredients of paint, 70 2. Types of paints, 70

3. The painting process, 7] 4. Common painting defects and remedies, 72 CHAPTER 13. INDIAN INSTITUTE A. Rules & Regulations, 73 B. Code of conduct, 78

OF INTERIOR DESIGNERS

DRAWING

73-80

PAGE NO.

1-5

A. LETTERING & SCALES I. Lettering, ] 2. Scales, J B. FIGURES & PROJECTIONS I. Geometrical Figures, 6 2. Orthographic Projections, ]4

6-19

C. ,BUILDING MATERIAL SYMBOLS

20-20

D. SPACE STANDARDS

21

- 22

E. EXTERNAL PARTS I. Brick Bonds, 23 2. Plan. Elevation and Section. 28 3. Typical Wall cross-section, 30 4. Arches and Lintels, 33 5. Types of Arches, 36

23

-

F. )NTERNAL PARTS I. Wooden Joints, 38 2. Doors, 42 3. Windows, 46 4. Wooden Panelling, 49 5. Partition Wall, 5] 6. Suspended Ceiling, 53 7. Modular Furniture, 55

38-56

G. KITCHEN DESIGN H. STAIRCASES

57- 59 60-66

37

1. Dog-Legged Stairs, 6] 2. Spiral Stairs, 63 3. Geometrical Stairs, 65 I.

THEORY OF COLOURS J. Colour Wheel. 67

67- 75

3. Contrast Colour Scheme I, 72 4. Contrast Colour Scheme I, 74

J.

RENDERING

K.

THREE DIMENSIONAL VIEWS I. Isometric view, 78 2. Axonometric view, 86 3. Perspective Drawing Principles, 94 4. Perspective (I-point), 95 5. Perspective (2-point), 101

TECHNIQUES

76 :...77 78 - 106

L. INTERIOR DESIGN METHOD I. Organisation of Space, 107 2. Interior Layout of a Residence, 109

107 -

114

M. INTRODUCTION TO COMPUTER AIDED DRAFING (CAD) t. Facilities in CAD system, 114 2. Advantages of using CAD, 114 3. Auto CAD (ReI. 10) design software package~ 114

liS -

122

1. INTERIOR DECORATION AS A PROFESSION The profession of 'Interior Design' did not exist before 20th century. Traditionally the carpenter ,or the store-keeper used to advise the arrangement of interiors for their clients. Until the First World War interior decoration was closely related to the trade of antiques. The social and economic situation during the 20th century increased the importance of an interior decorator. Interior decoration still remains a ld?'ury available only to the upper classes of the society. Certain status is attached in the society in taking professional advise on the appearance of home or'\vork-place. The role of interior decorator is always advisary because of the consultative nature of the work. It is one of the professions in which women did very well. In America, women tried to establis,h economic independence through interior decoration of existing buildings or rooms. Interior decorators were mainly responsible for selecting suitable textiles, floor and wall coverings, furniture, lighting and colour schemes for rooms. Interior decoration never enjoyed the status of architecture and the interior decorator is rarely responsible for structural alterations. It is regarded as a branch of fashion design because in interior decoration very few schemes remain .intact for a long time. Interior decoration gained importance with the publication of the book, 'The decoration of houses' by novelist Edith Wharton and 'good taste' architect Ogden Codman in 1897. They identified the principles of proportion and harmony for the planning of interior schemes. The criteria

~

dominated the profession.

"

2. EMERGENCE OF PROFESSIONAL INTERIOR DESIGNER The status of an interior designer did not improve further due to the Second World War shortages. Then the emergence of interior designer with ,

professionalqualificationstarted to dominatethe interiors.These designersworkedon non-domesticinteriorsbecausethe commercialsector realisedthe worth of good interior design. During and after the Second World War, modernisation was developed in America. Among the prominent modem architects in America, Mies Van der Rohe, designed exposed steel-frames and brick-and-glass infills. Different functional areas were delimited by storage units not reaching the ceiling. Many of the technical innovations of post-war interior design are widely used in the interi~rs. 3. MODERN

INTERIOR

DESIGN FEATURES

Let us discuss some important interior design features in modem buildings. The false ceiling of each floor conceals services such as air-conditioning and electric cables. They can be easily accessible for maintenance through the false ceiling. The interior working space was opened with rows of desks and small p~itions replacing corridors and office rooms. The concept of an open-office was developed during the 1950's with large floor areas divided by partitions, \

d~sks, filing cabinets and plants. The working environment is totally controlled with air-conditioning and artificial lighting. The natural elements are introduced with floor carpets, indoor plants and the use of sky lights. Another interior design feature is to leave interior brickwork and concrete exposed. New t~hniques for moulding and glueing plywood were discovered by American manufacturer~ during the War forth~ Navy. Th~se. are used for furniture design hke plastics with fibre-glass reinforcements, plastic shell chairs on metal legs, wire chairs, stacking plastic chairs. bent plywood chairs and black leather

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

2

upholstery. Open shelving, drawers, cupboards and desks replaced partition walls. Thus a good interior design was defined as 'items in which the design was simple of good proportions and without dust collecting features with stress on good construction'. Manufacturers were allowed to produce their own designs and there was public demand for ornament and periodic design features. Certain features of modem interiors are indoor plants, built-in furniture, animal skins as floor coverings, Venetian blinds, open storage space and smooth organic forms. There is a tendency to use different textures and patterns. Free-standing lamps replaced wall and ceiling lamps. The garden is integrated with the living space by a sliding glass door. The discovery of new building materials led to many more innovative interior design concepts.

EXERCISE 1. Describe the emergence of professional interior designer? 2. What are the important features of modem interior design?

The main source of design has been nature for man and his creations. From nature many aspects has been picked up for various designs.. To communicate these thoughts, there is a need to develop a design language. Broadly we can divide them into two groups. .

.

t'

These are basically visual components used in creating an object or a composition. They can be classified into: . (B) Form (A) Line' .(D) Colour (C) Texture (E) Pattern (F) Light

.

2. THE PRINCIPLES These principles help us in determining an object, whether it is artificialty good or bad in appearance. They can be classified into:

(A) Balance

(B) Emphasis

(C) Rhythm (E) Unity or Harmony

(D) Proportion

Let us discuss t~e 'Elements' in detail

'

, '

1. A. Line - Line is the basic design element. Too many lines of different nature in a room create an impression of visual chaos like too many beams, panelling on walls etc., Lines should be restricted to the minimum. Equal heights in furniture bring in the impression of unity in the space. Vertical lines create the imPression of height and similarly horizontal lines create the impression of more length. Vertical lines of door ways, draperies, windows, built-in

cupboards give strength and height to a room. Similarly horizontal lines are obtained by tables, chairs, book cases etc., 1. B. Form It is also referred as shape, area or mass. Forms are closely related to lines.,Forms unite with lines to achieve overall design of a given "

.:..

space. A long rectangular table or sofa helps in creating a line of unity in the room but at the same time too many shapes or formS of furniture create the

impressionof chaos. 1. C. Texture - Surface characteristics of any object is known as texture. Text~aJ surfaces range from smooth to rough. A rough texture absorbs light ,

'

4 and smooth surface reflects light. Small and dark rooms should have smooth texture and large rooms can have rough texture, if needed. Textures can be used

for wall finish, woodwork, furniture etc.,

1. D. Colour

.

- We react

emotionally to different colours in different ways. Our national flags and political party flags are good examples of our attachment to various colours. We all know that colours are an integral part of our religion and culture, so the choice of colour is very important and relative to the functional use of space. Light is intimately linked with colour because light is the source of all colours in nature. Bright colours should be used in dark areas and dark COIOurfcan be used in lighted areas. There are wide variety of colours for interior surfaces. A careful and thoughtful use of colours is very essential for attractive interiors. 1. E. Pattern - Pattern is a kind of surface enrichment. Any room will look dull without any pattern. In interior design there are three types of motifs or units of design. (a) Naturalistic motifs, which look like picture of flowers, fruits, animals or scenes. (b) Stylised motifs, which depend upon the material as well as purpose of the article. Ferns and leaves are the most commonly used pattemmodels for fabrics and other decorative articles. (c) Geometrical motifs, which are based on forms of circle, rectangle, triangle etc., Stripes, dot and checks are the most commonly seen geometrical .

motifs in interiors.

.

1. F. Light - Light is an art and utilitarian element. Light is closely related to colour and texture. Daylight is very important in the overall appearance of a room. Artificial lighting has become common in interior design today due to the lack of natural light in the interiors. There are many reasons for this. Many designers prefer artificial light for dramatic effect of interiors. However a good combination of natural and artificial lighting will save energy consumption. Artistic placement of lights can bring out important areas and keep subordinate areas in shadow. There are several types of artificial lighting appliances available today for interior designers. Now, let us discuss the 'Principles' 2. A. Balance - Balance is equalisation of attraction on both sides of the centre. There are two types of balance. (a) Symmetrical or Formal When articles of equal weight are placed on each side of the centre and at equal distance from the centre, then it is called as symmetrical or formal balance. (b) Asymmetrical or InformalIf each side of balancing point is ditferent and there is no centre line whichdivides the composition into two equal parts, t.l)en it is called as asymmetrical or informal balance.

in detail

5 2. B. Emphasis - Emphasis helps to centre the interest to the most important thing or spot in any arrangement. It should be called as focal point or cenVe of interest. If there is one main emphasized point in a room then others will become subdued. Few examples are a window, an arch. a painting and a furnitUre piece. The point of emphasis should be decided by the interior designer.

Fig. 2.3. Emphasis

2. C. Rhythm - Rhythm is the movement of the eye' across a design. It is a kind of organised movement in continuity. Rhythm develops through repetition of shapes, lines or colours.

Fig. 2.4. Rhythm

2. D. Proportion - Proportion is the consideration'of weight. shape and division of an object. It demands that all space divisions should be pleasingly related to each other. For example the division-of a room (4.0 x 6.0 m) as shown below.

6 2. E. Unity of Harmony - When all the elements of design are nicely related, then the design has unity or harmony. For example if all items have same colour or similar type of wood or. similar furniture design or similar fabric design. All forms, lines, textures and colours should be harmonious. The colours need not be the same always, but they can be complementary or matching one another. J.

\J'Jl.J1..1r..l.,

lUr..ftl.,

~L\.-lftl"'\JLL

\

The proportional system most associated with Greek architecture and design, and with classical architecture as a whole is called the 'Golden section or Golden mean'. Gold is the most uncorruptable and perfect of all the metals, so similarly this propotional relationship is also believed to be perfect. It can be described as the relationship of two unequal parts, where the ratio of the smaller part to the larger pan is the same as that of the larger part to the whole. The ratio can be approximately assumed as 1:I.6~ It can also be wriuen algebraically. Assume 'a' as the..maller unit and 'b' as the larger unit, then the relationship

. can be expressed as below

"

-.......

A G()lden mean rectangle can be generated from a given square. First the square is divided into half, then the diagonal of one of these rectangles is rotated d6wn along the side of the original square. From the end of the rotated diagonal the desired Golden mean rectangle is constructed. Example: Assume a square of 4.0 x 4.0 metres. * Draw a square of ABCD 4.0 x 4.0 m. in any convenient scale. * Divide the square into two equal parts of A~D and PBCO. * of OB and calculate its length based on the formula OB I * Draw a diagonal . It is 4.47 m. Draw the diagonal arch OB cutting at F. * Calculate area of larger part (b) or ABCD. It is 16 sq. m. * Calculate area of smaller part (a) or BEFC. It is 9.88 sq. m. * Add the areas of (a + b) or ABCD + BEFC..It is 25.88 sq. m. *

EXERCISE 1. What are the elements of design composition? 2. What are the principles of design composition? 3. What is 'Golden mean rectangle' ? Descri~ with an example 'J

Buildings are made of different kinds of mat~rials. It i~ very important to know thes~ building materials. The knowledge of different building materials, their properties and uses help in achieving economy and efficient use of materials. The cost of materials in the construction of a building ranges from 60 to 70 percent of the total cost. Some essential building materials are described below. Many new building materials are combinations of these materials or further innovations of these materials. However, there are many other new building materials in the market, so it is also necessary for the Interior Design~ to . get acquainted with them for creative interior designing.

1. STONE There are many varieties of stones available in nature. They can be broadly classified as below: (A) Different types of stones (a) Sand stone (b) Lime stone (c) Slate (d) Marble' (e) Granite if) Basalt (g) Laterite (a) Sand stone - It is very easy tp dress and work. It is extensively used in general ,building cQnstruction and ornamental carving. (b) Limestone - Lime stone slabs are used for floor41g, paving and roolmg. It is also used for general building purposes and manufacturing of lime. (c) Slate ~ Slates are used as a roofmg and flooring material. Harder slates are used fot damp-proofmg and steps of staircases. (d) Marble -'- It is extremely suitable for ornamental and superior type of building work. It is also used for flooring and other decorative works. (e) Granite It is very hard and durable stone suitable for bridge abutments, piers etc., It is not suitable for carving. (j) Basalt - It is hard and compact and hence very expensive to wor~. It is used in foundations of structures and superstructures also, but not used for ornamental work. I (g) Laterite - It is normally used for inferior type of stone masonry work. B. Stone aggregate - Aggregate is a general term applied to all inert materials which when bonded together with cement form concrete. C. General properties (a) A good building stone should be hard, tough, compact grained and unifonn in texture and oolour.

-

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

8

(b) (c) (d) (e) (j)

Stone absorbing less water is stronger and more durable as it will have less action of rainwater. Stone should be properly seasoned by exposure to the air before they are put in a structure. They should be small enough to be lifted and placed by hand. Length should be three times of the height and breadth, and it should not be less than six inches. Maximum height should be one foot. All stones should be wetted before use.

D. Stone masonry types (a) Random rubble masonry (b) Coursed random rubble masonry (c) Square rubble coursed and uncoursed masonry (d) Ashlar (a) Random rubble masonry - The stones are hammer dressed on the face, sides and beds to such an extent that the stones will come into close proximity with the neighbouring stones.

Fig. 3.1. Random Rubble Mason!)' (Uncoursf'.d)

(b) Coursed random rubble masonry - Stones are hammer dressed on the bed and LOPsurfaces until the stones give parallel faces. No face stone should '''be narrower or shorte.r than its height.

Fig. 3.2. R~dom

Rubble Masonry (Coursed)

(C) Square rubble coursed and uncoursed masonry - Stones should be hammer or chisel dressed on all beds and joiilts so as to make rectangular shapes.

Fig. 3.3. Square Rubble Masonry (Uncoursed)

Fig. 3.4. Square Rubble Masonry (Coursed)

INTRODucnON

9

TO BUILDING MATERIALS

(d) Ashlar - Every stone should be chisel dressed on all beds and joints to be true and square giving perfectly vertical and horizontal joints with the adjoining stones.

Fig. 3.5. Ashlar

2. CLAY PRODUCTS The different varieties of clay products are: (A) Bricks (B) TIles . (C) Terracota (A) Bricks The manufacturing of bricks involves four distinct operations. They are earth preparation for bricks, moulding, drying and buining. The

-

normal sizes of bricks available in India are 9" x 4 (a) Brick properties

--

r

x 3" and 10" x 5" x :

The surface should not be too smooth because mortar will not stick to it. * A brick should give a metallic ring when struck with a small hammer or another brick. * A good brick should not break when struck against another brick or ,,,hen dropped flat from a height of about four * to five feet. * It should have a surface so hard that cannot be scratched by fingernail. All bricks should be soaked in water for about one hour before use. * (b) Bricks are extensively used for construction of building exteriors and interiors in India. (B) TIles - They can be divided into two classes. (a) Common tiles used for rooImg, paving and draining, (b) Encaustic tiles used for decorative purposes, (c) Properties of tiles - TIles are made more Dr less in the same manner as bricks but they are.made thinner for the sake of lightness and width wise larger so that the number of joints may be reduced. (d) TIles can be classified into: 1. Flooring tiles 2. RooImg tiles 3. Quarry tiles.

4. Glazedearthenwaretiles

,

1. Flooring tiles - The tiles should be uniform in size, shape and free from irregularities such as twists, bonds, cracks and laminatio~. Square tile siZes are 15 x 15 ems with 18 mm thickness, and 20 x 20 cms with 20 mm thickness:2. Roofing tiles - There are number of vaqeties.of interlocking type roof tiles used for sloped roofs and have been patented by some companies. These are generally rectangular in plan. For example Mangalore tiles, Allahabad tiles, flemish tiles and country tiles.

INTERIOR DESIGNS PRINCIPLES AND PRACfICE

10

3. Quarry tiles - These are very dense and possess a good wear resisting property. They are used for heavy wear or chemical resistance flooring. 4. Glazed earthenware tiles - The top side of the tile should be glazed and the underside should be completely free from glaze so that the tiles may stick well to the surface. The edges should be free from glaze. These are generally used in finishing floors and walls of kitchens, bathrooms, water closets and .

hospitals,wherecleanlinessis important. 5. Terracota - It is a kind of earthenware made from superior clay by burning. Hollow terracota blocks are used as a substitute for stone in ornamental parts. Porous terracota is a fire resisting material.

3. CEMENT The best variety of artificial cement is known as 'Portland Cement' or 'Ordinary Cement'. It mainly consists of three ingredients lime, silica and alumina. Lime 60 to 65 percent and silica 20 to 25 percent. give the required strength, alumina 4 to 8 percent for quick setting and rest 2 to 16 percent are meant for hardness and colour. Manufacturing of dment by wet process can be-divided into three stages..First stage is mixing of raw materials, second stage is burning and third stage is grinding. There are other varieties of cement apart from portland cement, they are as described below: (A) Rapid hardening cement - This type of cement attains high strength in early days because of increased lime content in composition and bumingat higher temperature and finer grinding. This type of cement is used in concrete when earlyhigh strengths are needed either to remove form work quickly or speedy construction or in cold weather conditions to reduce the period of protection against low temperature or to achieve economy for early higher strengths. (B) Quick selling cement - This type of special cement starts setting within five minutes of water addition and becomes bard like stone within thirty minutes. This is produced by adding small percentage of aluminium sulphate as an accelerator and also by reducing percentage of gypsum and fine grinding. This type of cement is used where the work has to be completed in a short time. For example cement concreting in static or running water. (C) White cement - This is a variety of ordinary cement and prepared from such raw materials which are practically free from iron oxide. It is more

costly and used for architectural decoration purposes. I(D) Pozzalona cement- Pozzalona is a volcanic powder found in thermal plants. It is mixed with cement clinker to prepare cement. It is used for ~ structures, sewage works and other underwater works. This can also be used for internal plastering for economical building construction. 4. MORTAR It is a mixture of binding material (like cement and lime), fine aggregates (like sand) and water. This is used to bond masonry or other structural units. The uses of mortars are as mentioned below: To unite bricks or stones in the construction of brick and stone masonry. * To form an even bed between different courses of masonry.work and to distribute the load evenly on the layers. * To hold stone aggregate together and form a solid mass of concrete. * To cover exposed surfaces of walls and joints with plaster to provide smooth and hard surface. * (a) Different varieties of m~rtar mortar - It is a mixture of lime, sand and water. Lime acts as a binding material for preparing mortar when it is to be used in masonry work. Generally lime to sand ratio is 1:2.

lime

*

Ce"rent mortar - It is a mixture of cement, sand and water. Where cement acts as a binding material. The proportion of cement to sand varies from 1:2 tC' 1:6 depending upon the desired strength. Surkhi mortar - It is a mixture of lime, surkhi and water. Here sand is substituted by surkhi for economy and strength. Surkhi is a form of finely burnt

* * .

clay.

..5. CONCRETE It is the most versatile material for all types of construction. It is mainly used in building construction for foundations, columns, beams, slabs, staircases, lintels, sunshades, door & window frames, storage water tanks etc., There are many varieties of concrete. They are:

/

INTRODUCfION

TO BUILDING MA'JERIALS

11

(A) Plain cement concrete, (B) Reinforced cement concrete (C) Prestressed concrete (D) Lime concrete (E) Reinforced brick concrete. (A) Plain Cement Concrete - It is a mixture of cement, water and aggregate. It has high compressive strength. It has good workability as it can be moulded into different shapes. It has high durability value and not much affected by atmospheric conditions. It is a good insulator and has a fairly good fire

resistance.

.

(B) Reinforced Cement Concrete (RCC) - In reinforced cement concrete, both concrete and reinforcing metal (usually steel) are combined to act together as one material and produce a more economical material than either acting alone. A general proportion of mix is 1:2:4 for general work. (C) Presttessed Concrete - This is a modification over RCC in which steel provides high initial compressive stresses in the concrete so that it may resist tensile stresses without cracking. Prestressed concrete saves upto fifty percent of concrete and quantity of steel is also reduced as high tens.!!~ steel is used. (D) Lime Concrete - It is a mixture of lime, fine and coarse aggregates and water in 1:2:4 proportion. (E) Reinforced brick Concrete - It is known as RBC. In reinforced brick concrete, steel rods are embedded inrement concrete which take teJlSion

whereas compression is.taken by brick. This is cheaper than RCC.

.

6. TIMBER Timber is that part of wood of a tree which is of sufficient size and can be used for builQing, carpentary and various other construction purposes. Some trade names of timber available in the market are Babul, Deodar, Teak, Sal and Walnut. Timber is available in different forms. They are: Converted timber, which is sawn and cut into suitable commercial sizes. * j Rough timber, which is ?btained after falling a tree. * Standing timber, which is available in a living tree. (A) Properties of good timber Timber should have sufficient weight. A timber with heavy weight is considered to be sound and strong. * The structure of timber should be uniform, hard and compact. * It should have favourable physical characteristics such as dark colour, straight fibres,. and shining appearance. It should be free from defects and good * sound rSl10UIdemit when struck.

(B) Seasoning of timbers

.

This is the process of drying of timber in order to remove all the plant juice and moisture out of it so that it will not decay. Seasoning of timber may be done naturally- or artificially. . (C) Preservation of timber It is the process of preserving the timber structure from the attack of destroying agents like moisture, fungi and insects to ensure increased life. Some of the preservatives used are oil paints, coal tar and chemical salts. 7. PLYWOOD AND RELATED PRODUCTS Timber, which is scientifically prepared in factory to meet the desired shape, appearance, size and strength is termed as 'industrial timber'. Industrial timber is available in various varieties such as veneers, plywoods, laminated timber and block boards. Such varieties are: (A) Plywoods (B) Fibre boards (C) Block boards

12

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

Veneers are thin sheets or slices of wood of superior quality, which are knife cut by various processes. Thickness varies from 0.4 to 0.6 mm or even more. Veneers are used to produce plywoods, batten boards and laminated boards. This process is known as veneering. (A) Plywoods - These are prepared by cementing together thin boards or sheets or'wood into panels. Three or more veneers, which are always odd in numbers are placed one above the other so that the grain of each layer is at right angles to the grain in the adjacent layer. The main advantage is uniform strength and greater resistance to cracking and splitting with change of moisture content. The veneers are held by suitable adhesives like synthetic resms. They are available in standard sizes and thickness. It is used for interior partitions, doors and panelling. (B) Fibre boards These are rigid boards, which are prepared after processing pieces of wood, cane and then pressing them together. It is also known as pressed wood and available in various forms like laminated boards and hard boards. They are used for wall panelling, suspended ceiling and partitions. (C) Block boards - Block board has a core made up of strips of wood glued or joined to form a slab, which is further glued between two or more outer veneers in such a way that direction of the grain of the core blocks running at right angles to the adjacent outer veneers. These boards are Qf two types,

-

.

commercial and decorative. It is used for furniture, panelling and partitions.

8.PLASTICSANDRELATEDPRODUCTS

,..

\

Plastic is an organic material of high molecular weight, which is soft enouglf at some stage of its manufacture to be formed in various shapes by aptftymg

beat and pressure. Plastics are broadly classified into different types depending upon their behaviour when heated and cooled during manUfacture. (A) Thermoplastics - These plastics are softened by heat during the manufacturing process and regain their original properties as they solidify duriQg .

'

cooling to form the fInished product. Some of the uses are PVC tubes, wall tiles, floor tiles and glazing. (B) Thermosetting plastics - These plastics change chemically when heated during manufacturing. They solidify while still hot and assumetli~'iQrii1 of finished product. It is not possible to reshape these plastics by means of heat and pressure. Some of the uses are Wash basins, water closets, vMves,haIidles and wall panels. '~ 9. GLASS AND RELATED PRODUCTS Glass is a mixture of number of metallic silicates like pure sand, soda, chalk and one of which is usually an alkali metal. Various varieties.~ developed in recent tiiI}es. Some of them are:

gi~are

INTRODUCfION

13

TO BUILDING MAlERIALS

10. PAINTS AND RELATED PRODUCTS Paints.are the coating of fluid materials applied as a final finish to all surfaces like walls, ceiling, woodwork and metal work. (A) Characteristics of a good p~int (a) It should possess good spreao~g or covering power. (b) It should be cheap and economical in the long run with easy applicability and drying capacity within a day.

(B) Types of paints

.

(a) Aluminium paint - This paint c~sists of finely ground aluminium suspended in varnish and ~ evaporation of varnish spirit or oil, the particles of aluminium form a thin coating on the surface. It is used for metal roofs, gas tanks, eledtReal and telephone poles and machinery. (b) Anti-corrosive paint - It consists of oil, a strong drier and a pigment mixed with fine sand. It gives black appearance to the surface. It is ..sed to

preserve steel work from corrosion. (c) Bituminous and Tar paints - These paints consists of bitumen or tar dissolved in petroleum or spirit. They are alkali resistant and possess high . . covering power. They are used for painting steel, brickwork exterior and roofs. ' .

(d) Cement paints

- This

'

consists of boiled linseed oil into which dry good cement (65 t075 percent) is mixed so that a paint of workable consistency is

obtained. Cement paint is available in powder form in variety of shades. It has Ibetter water proof qualities, strength, hardness, durability and decorative appearance. It is used for p,lastered brickwork, stone masonry and concrete. It lasts minimum five to six years before renewed painting is ~~ Emulsion paint - This paint consists polyvinyl a~etate, synthetic resins etc., giving excellent quality of alkali-resistance. It has good workability, high '

(e)

,

"

durability and quick drying. It is used for masonry surfaces.

.

. '

if>Enamel paint - This paint consists of metallicoxide ground with a small quantityof oil and mixed with petroleumspirit for holding the paint together. It is available in ready made form in variety of colours. It dries slowly but after drying it forms a smooth surface. It is not affected by hot

and cold water and steam,and it is easilywashable.It is used both for internaland externalworks. (g) Oil paint

- This

,

is the ordinary paint. The oil paints are used in. general for all types of surfaces such as'wood work, walls, ceilings and metal work.

Three coats like primer, undercoat and finishing coat are necessary for internal work.

'

(h) Plastic paint - It consists of a variety of plastics as the base. When this paint is thinned with water, it is known as 'plastic emulsion paint'. It has

decorative appearance, high covering power and quick drying. They are widely used for showrooms, auditoriums and cinema halls.

'

(i) Distempers - They are considered to be water-paints consisting of whiting or chalk powder, glue as a binder and suitable fast colouring pigments. These are cheap, durable and easily applied on plastered, cement concrete and wall board surfaces. '

11. FE~ROUS

AND NON-FERROUS

-

METALS'

(A) Ferrous metals All such metals containing iron as their main constituent are termed as ferrous metals. (a) Cast Iron ~ It is ItlaIlufactured by refining pig iron in a cupola furnace. Carbon content in cast iron varies from 1.7 to 4.5 percent It is strong in ,

compression and weak in, tension. It cannot be welded, rolled, puncheq or riveted but caD be melted and cast into various. shapes and rusts slowly. It . is used for making builcfu\g column brackets, spiral staircases, manhole covers, ra;.n water pipes and sanitary fittings. (b) Wrought iron - It is the p1.\re~tform of iron with low carbon content (less than 0.15 percent) It is hard and can be bent, twisted, rusts more quickly

than cast iron. It is replace~ brmild steel at present, so it is produced in small quantity. It is used for making tough materials such as nails, bolts, chains, sheets, handrails an4 ornamental gates. "

(c) Steels - Steel is an alloy or compound of irOn and carbon in the form of carbide of iron. The carbon percentage is limited to 1.5. There are three "

grades of steel in accordance with the percentage of carbon.

"

'

1. Low carbon or mild steel. 2. Medium carbon or hard steel. ,.'

3. High carbon steel."

,

The increase of carbon percentage increases the tenacity and hardness. Steel is used for trusses, beams, griiIs, mechanical devices and sheets.

INTERIOR DESIGNS PRINCIPLES AND PRACflCE

14

(B) Non-ferrous- metals - These are the metals which do not contain iron as their main constituent. They are of several types. Three of these metals are

of important use in building industry.

.

.

(a) Aluminium - It is silvery white lustrous metaIobtained from 'Bauxite' ore. Pure aluminium is very soft and it is mixed with other metals like copper, magnesium, silicon, manganese and others to increase tensile strength and hardness while retaining the character of lightness and durability. It is . corrosion resistant and good conductor of heat and electricity. It is used for roofmg, window frames, glazing bars, posts, panels., wires and in paintS. (b) Lead - It is bluish grey in colour with silvery lustre when freshly cut and available in free state. It is resistant to atmosphere corrosion and not affected by soil,. sewage and industrial wastes. It is used for roofmg, water service pipes, cable coverings and ornamental work. (c) Copper - Copper. is extracted by smelting 'Copper Pyrites' which is an ore of copper. Pure copper is of lustrous red colour, light, tough and good . conductor of heat and electricity. It is used for electric wires, cables, roofing and electroplating. C. Alloys It is an intimate mixture of two or more metals. The properties of an alloy are entirely dim~rent from those of its constituents.

-

(a) Brass

- It is all alloy

of copper and zinc. Commercial brass contains 65 percent copper and 35 percent zinc. Properties of brasses vary considerably

by changing these proportions. It resists corrosion but needs regular cleaning. It is used for door and window fittings, household utensils and hardware. (b) Bronze - It is an alloy of copper, zinc and tin containing 80 percent copper. Bronzes are hardened copper. They are stronger and superior to brass in cOrrosionresistance. It is difficult to work and niore expensive. It is used for frames, grills and hardware. 12. GYPSUM AND RELATED. PRODUCTS . (A) Gypsum

-

It is a combination of calcium sulphate. with water and the white substance is found in the form of rock in nature. It is mainly used in th~ manufacture of cement to increase its setting time. .

..

(B) Plaster of paris (POP) - When finely ground gypsum rock is heated to a temperature between 100°C and 140°C, three fourth of the passes off as a steam. The remaining product is known as 'plaster of paris'. It is used for ornamental work and its products are hard-surfaced, contours and they are sufficiently strong. Gypsum plaster is rendered more plastic by the addition of clay on hydrated lime. Its cohesiveness adding hair or shredded wood fibre. . (C) Plaster board - It isa large sheet of gypsum plaster faced on both sides with stout paper as a reinforcement. Depending upon the

. paper, plaster boards are of two types. They are: 1. Gypsum lath board, when the .facing paper is rough and provide adhesive grip for plaster finish.

combined water can have sharp is increased by . nature of facing

.

2. Plaster wall board, when facing paper is of self-finish type for decoration. They have good insulation properties and used for ceilings and partitions. . (D) Asbestos - It is naturally occuring mineral substance composed of hydrous silicates and contains small amount of" iron oxide and alumina. It is largely uSed for preparing Asbestos Cement, which is used for making pipes and roofing material. Asbestos felt is used as damp' proof layer for insulation and . as lining material. 13. ADHESIVES

(OR GLUES)

An adhesive is a substance which enables two surfaces to stick together and behave as a single unit. They are classified into two types: Organic adhesives are made out of animal blood albumin, vegetables, milk and other organic wastes. (B) Synthetic adhesives are permanent, strong, water proof and made out of chemical resins.

(A)

EXERCISE 1. Describe the properties and uses of the following building materials: . (b) Clay (a) Stone (d) Mortar (e) Concrete 2. Describe the properties and uses of the following building materials: (€i) Plywood (b) Plastics (d) Paints (e) Metal.s

(c) Cement (j) Timber (c) Glass if) Gypsum

In the present context, plumbing services mean Water supply and Sanitation including sewerage and drainage. The importance of plumbing services is well known in a building. This knowledge helps an Interior Designer to plan the interiors efficiently keeping in view of these service requirements. 1. WATER SUPPLY ..

A. Water supply in residential buUdings Public water supply system consists of collection, conveyance, treatment and distribution. Water is distributed for consumption in a building through internal water distribution system. Water supply in a building depends on the size :md height of the building. Large and tall buildings create numerous

.

16

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

installation and design problems, whereas in low rise buildings they are not found. Water piping system may be basically horizontal or vertical. Systems above the .main or pressure tank are called upfeed systems. In tall buildings water is pumped to elevated tanks, so that it can flow down. Adequate water is needed for drinking, fire protection and general use. Before designing a building water requirement should be calculated keeping the present and future needs of the 9ccupants. Availability of sufficient quantity of water sources like municipal water, ground water and surface water should be found. Normally municipal water is treated and supplied, whereas ground and surface water should be properly treated as per the need . of the users. Distribution of water is

done"with pipes internally in a building.

'Residential buildings are nOrmaHy-ooe-- t~
ground or basement floor to supply both drinking water and general purpose water. From this tank, water is pumped to the roof level for storing separately for drinking and general use. From these storage tanks, water is supplied by gravity pressure in separate pipes for drinking and general use.mfuth the systems wider is pumped to the roof level with motor.

C. Piping materials Cast iron, steel, concrete and asbestos cement are the most common materials used in distribution pipes. Copper, lead, Zinc, brass, bronze and plastic are used in small pipes, valves, pumps and 'other appurtenances. Common pipe joint materials are lead, cement, sand, rubber, plastic and sulphur compounds. Stoneware pipes are mostly used for underground work. Cast iron is the most common material for city water mains. Steel is commonly used for large pipelines and trunk mains but rarely used for distribution mains. Concrete pipes may be precast in sections and assembled on the job or cast in place. Hume

.

.pipes are RCC pipes used for drainage,irrigation,wells and culverts.Galvanisedpipes of steel or wroughtiron are widelyused for distributionsystems. Thes~ pipes are used where pipes are to be exposed to corrosive conditions such as salt water or air. Lead pipes are not generally used for domestic water supply. They can be used for flushing and overflow pipes inside the buildings. PVC pipes are more flexible, conosion resistant, light weight, easy to handle and install. It is comparatively cheaper. They are not suitable for hot water installations.

2. SANITATION Water after usage becomes waste water, which should be collected and conveyed through drain pipes to join the municipal sewers laid under the roads. The surface and rain water is also let into the sewers in the combined drainage system. The waste water is let into the municipal sewers through underground chambers like manholes connected by traps like gully trap, intercepting trap, grease trap, silt trap and ventilating pipes. The primary function of the trap is to seal the foul air entering the building. A. Traps Traps prevent entry of foul gases and odour from municipal sewers and drains. Depending on the need, a water seal is created as a barrier. The depth of the water seal can be between 35 rom to 75 rom. These traps should be created as close to the unit as possible. Efficiency of the water seal depends on the depth of the water. Traps should be made of non-absorbent material. Entry inlet into a drain should be properly trapped with a water seal. It should be provided with a cap or plug for cleaning. Traps can be made of different shapes. Most conimon shapes of traps are p. Q and S. (See Fig. 4.1,4.1.2, 4.1.3) (a) Gully trap'- Gully traps disconnect the sullage drain of the house from the main drain. They are employed to receive sullage or waste water from wash basins, sinks and baths and pass it on to the house d'mns. Gully traps should be fixed near the surface level of the flOQr.There should be a

grating on top of the tiap to block solid matter. Pipes should be connected to the gully trap below the grating. In combined system of sewage the rain water is also passed into the house drains through the gully traps. (See Fig. 4.1.5). (b) Intercepting Trap - It is also known as 'sewer'trap. It disconnects the house drain from the street sewer. It can be fixed in the last manhole of the house or in a separate small chamber between tbe lowest end of the house drain and the street sewer. It has a comparatively deeper water seal than ordinary trap and an opening at the top of the trap known as 'cleaning eye'. This opening is closed with a plug. The intercepting traps should be properly flushed out otherwise they wilJ not be of much use. (See Fig. 4.1.4). (c) Grease trap - Grease traps are used where large quantities of oily wastes are let out into the drain like hotels, restaurants and some industries. These oily substances deposit solids in the house drains and municipal sewers. To avoid this, grease traps are used. Grease trap can be a small cast iron or masonry chamber with a bent pipe as on outlet. The oily substances float to the surface to form a scum on top. The bent pipe allows the sewage to flow out while retaining the scum. This scum cari be removed out from the top. (See Fig. 4.1.6). (d) Silllrap - Washing of kitchen utensils, sometimes, involves ash and pulverised brick pieces. These particles need steep slopes and higher velocities

.

PLUMBING '.!

19

",

in the drain for movement. These should be trapped and removed in silt traps. These silt traps are required where extensive utensil washing is carried out like hotels and restaurants. Silt and grease traps can be combined.' B. Waste Water Disposal Waste water Disposal is done through inspection chambers or manholes, septic tanks and with proper ventilation systems. (a) Inspection chamber or Manhole - For cleaning, repair and inspection of house drains masonry inspection chambers or manholes are constructed on house drains. It is provided at every junction or change of direction or gradient and at 30 m intervals in the long straight lengths. TIle drainage pipes are opened out in these chambers to form channels. The bottom is given steep slope towards the open channel in the centre of the chamber. This prevents blockages and deposits of soil in the pipes. The chambers are closed from top with cast iron covers to prevent escape of foul gases. The size of the chamber depends on the underground depth and number of branches to be connected (See Fig. 4.2.1). (b) Septic tank - The function of a septic tank is to produce some biological changes of the human excreta and reduce the bulk of sewage. This system is useful where municipal sewerage system is not available. In the septic tank lighter matter rises to the surface and form a thick layer called 'scum' while heavIer matter sinks to the bottom as 'sludge', The tanks are made air-tight, water-tight and excluded from light to help the sewage decomposition process. The layers of scum and sludge are not disturbed. by the flow of water by making a vertical partition wall called as 'baffle wall'. The size of a septic tank depends on the number of users. A septic tank should be initially filled with water and constructed far away from the house. The effluent may be disposed into a cesspool. The size of the cesspool depends on the absorption capacity of the soil and the number of users. A cesspool is constructed with bricks or stones with open joints below the level of inlet pipe. The cesspool may be filled with gravel or brickbats at

the bottom. It should not be located within 30m radius of a drinking water well or bore well. (See Fig. 4.2.3).

.

(c) Ventilation systems - Ventilation system is necessary to let out the foul gases developed inside the drains. If the foul gases does not escape into the air, they may break the water seal of the traps. The ventilation ducts dilute the foul gases and their poisonous effects. These fresh air inlets can be provided by an outlet pipe directly connected to the underground drain or over the manhole and rise above the roof level of the building. The fresh air inlet should be vertical, about 100 mm diameter, atleast 3 m above ground level and with a slotted cast iron head on top. A long 30 to 50 nun diameter cast iron pipe is used as an outlet pipe. In addition to this, ventilation system should be provided on every soil and waste pipe of every water closet and bath. When wc's of more than one floor are connected with the same soil pipe, an anti-siphonage pipe or vent pipe is fixed to the outlet side to both the traps to prevent siphonic action and emptying of the sealed traps in the lower water-closets when the upper water-closet is flushed. The vent pipe should have a diameter of not less than 50 mm and connected at an angle of 45° from the highest part of the trap. The vent pipe can be taken up to the top of the soil pipe and provided with a wire globe. This vent pipe should be taken above the level of the building roof. (See Fig. 4.2.2).

c. Sanitary appliances There are various types of sanitary appliances available in the market..Most commonly used sanitary appliances are (a) Wash basins (b) Sinks (c) Showers (d) Bath tubs (e) Urinals (j) Flushing cisterns (g) Water closets (a) Wash basins - There are various types and shapes of wash basins for different uses. They are made of cast iron, steel, porcelain and plastic materials. The standard wash basin consists of a bowl, soap tray and holes for tap and water overflow. TIley may be supported on cast iron brackets screwed to the wall or on a pedestal concealing the pipework. They 'are normally fixed at 0.80 m above the floor level for convenience. (See Fig. 4.3.1). (b) Sinks - Sinks are normally used in the kitchens or at places where frequent cleaning is required Sinks are made of porcelain, steel and plastic materials. There are three types of sinks. They are Belfast type, ordinary type and stainless steel type. The belfast type has water overflow which passes water to the waste pipe. A drain board may be fixed on either side of the sink or the drain can be integrated into the sink. Ordinary sink is similar to Belfast type but it does not have proVision for water overflow. Stainless steel sinks have drain board on either side or on one side with single or double bowls as per the need. (See Fig. 4.3.2).

(c) Showers - Shower is most commonly used in the residences. It is more hygienic and takes less space and water. The mixer may be thermostatic or non-thermostatic. The shower tray is made of plastic and porcelain materials. The bore of the supply pipes is 13 mm and the pipes should be as short as possible to avoid frictional losses. The minimum height above the shower outlet should be 1.0 m. In place of a shower tray, hU'ger tiled space is also used for taking shower on some occasions. (See Fig. 4.3.4). (d) Bath tubs - Bath tubs are used in western type of toilets. Bath tubs are used for relaxed bathing. They are made of porcelain, steel and plastic materials. These tubs are provided with holes for hot and cold water pipes for mixing before taking bath. Provision is also made for water overflow and waste outlet. These bath tubs can be made of different fancy shapes and sizes. Normally the length varies from 165 to 180 cm, width varies from 55 to 58 cm and depth 40 to 45 cm. The bottom of the tub is supported with short legs on the floor. (See Fig. 4.3.3). (e) Urinals - There are four types of urinals called as Bowl type, slab type, stall type and squatting plate type used by ladies. Slab and stall type urinals are used in public toilets. The bowl type is screwed to the wall and if two or more bowls are fitt~d division pieces may be fixed between them. The slab type consists of flat slabs fixed against the wan with projecting end slabs an~ common channel. The stall type consists of curved stalls with dividing pieces and glazed channel. The foot rests should be non-slippery and sloping towards the channels. Ordinary brick walls with cement plastered surfaces are not suitable for urinals. They should be cladded with glazed tiles and joints should withstand the chemical reaction. The urinal waste pipes can be in plastic or lead with 50 mm diameter. Not more than seven urinals should drain into one outlet. Urinals are normally made of glazed tiles. porcelain and plastic materials. (j) Flushing cistern - Flushing cistern is a tank which discharges water for flushing out a water closet or urinal. Flushing cisterns are made of cast iron, porcelain and plastic materials. There are two types of cisterns, the bell type and the disc type, which are most commonly used. The bell type of flushing cistern is noisy. The cistern is operated by pulling down the chain and lifting the bell. When the water runs down it takes away some air and it results in vaccum on the tDp of the bell. The water gets empty within few seconds due to the syphonic action. The water to the cistern is supplied through ball valve arrangement. (See Fig. 4.4.3). The disc type flushing cistern is commonly used in all types of buildings. The cistern is operated by a lever which lifts the piston and water is tlushed by siphon action. (See Fig. 4.4.4). There arc other types of Ilushing cisterns like flushing trough and automatic flushing cisterns and valves. A flushing trough is used as an alternative to separate nushing cisterns for the flushing of more number of wc's. Automatic flushing cisterns and valves are also used for similar purpose in puolic toilets. (g) Water closets -- Waler closets can be classified into Indian and western types. In Indian type of wc, squatting pan is used. In western type of ~c, siuing pan is used. There arc two types of flushing systems adopted. They are wash down type and syphonic type. In the wash down type a high level tlushing cistern ahove the door level is used for flushing. In the syphonic type, a low level flushing cistern is used. The surfaces ofthe bowl are cleaned totally in this type. This is particularly used in western wc's. When the cistern is flushed the water flows through the outlet, which is designed to slow down the flow of water and the pipe is filled with water causing siphonic action. The siphonic wc's are comparatively quieter in operation. (See Fig. 4.4.1 & 4.4.2). (h) The following tables gives the different sizes of pipes for fixture supplies. Table 4.3. Different sizes of pipes

D. Plumbing systems

. There are four systems of plumbing for building drainage. They are: (a) One pipe system (b) Single stack system (c) Single stack - partially ventilated system (d) Two pipe system (a) One pipe appliances - In this system only one main pipe collects both soil waste and waste water from different appliances. In multistoreyed

buildings the lavatory blocks on different floors are placed above one another so that the waste water from different units can be carried through common vertical pipes connected by short branch drains. Thus only one main pipe. collects both soil and waste water from different appliances. This. main pipe is directly connected to drainage system. All traps of wc's and wash basins are completely ventilated whereas gully traps and waste pipes are not provided. (b) Single stack system - This is same as one pipe system but no ventilation of traps is provided. (c) Single stack-partially ventilated system - This is a compromise between one pipe system and single stack system. There is only one soil pipe for colfecting the discharge from all water closets, baths, sinks and basins. A relief vent pipe for ventilating only the traps of wc's is provided. (d) Two pipe system - In this system separate soil and waste pipe are provided. The soil pipes are directly cOIlllected to the drain, whereas waste pipes are coIlllected through a trapped gully. All traps are completely ventilated. In India, the two pipe system is comparatively more convenient because close grouping of fixtures is not necessary. However in multistoreyed buildings one pipe system is preferable because close grouping of toilets is necessary for convenience and economy. E. Residence drainage plan The Fig. 4.5 shows residence drainage plan. It is assumed that the drainage and sewer lines are combined.

EXERCISE 1. 2. 3. 4. S.

Describe the water supply systems in multi-storeyed buildings? Describe various traps used in the sanitation of buildings? What are the different wa.'Ite water disposal systems ? Describe the important sanitary appliances? What are the various plumbing systems adopted in buildings?

Ventilation means supply of fresh air and removing dust, heat and other pollutants for human comfort. Natural ventilation is very important for healthy living. 1bere are many buildings, which we see around us are very poorly ventilated. These poorly ventilated buildings' are not in city slums, but in densely built up areas, particularly in the centre of the city. As an Interior Designer, it is essential to ensure good natural ventilation in any building interior. Natural ' ventilation helps in improving hygienic conditions. For any type of interior design and planning, it is important to create healthy living conditions otherwise there is no difference between old and new buildings. Everything stands next only to this primary concern. 1. GUIDELINES FOR NATURAL VENTILATION A. The following factors should be taken into consideration for natural ventilation. (a) Room or building .size. (b) Activity performed in a room or building. (c) Number of occupants. (d) Heat and relative humidity. (e) Other pollutants like smoke, dust and fuw...es. B. AtIeast one window should be provided on the windward wall and another window on the opposite side of the wall. C. In case of a room with only one wall exposed outside, two windows are preferable' than a single window..

D. Windows located directly opposite to each other perform beUer.

E. Maximum air movemeIit is achieved by keeping the silI height at 0.75 m to 0.90 m from the floor level.

F. Verandah open on three sides increases air motion in an adjoining room.

.

G. The average wind velocity inside a room may be around 27 percent of the out door air velocity. H. Openings of equal size are preferred in regions having fairly constant wind direction. 2. MECHANICAL VENTILATION A. Ventilation with fans Mechanical ventilation is necessary, where natural ventilation is not possible and to remove pollutants. The use of mechanical ventilation will allow for provision of air temperature control, humidity and purity. Buildings of different use demand different quantities of fresh air for their occupants. It is expressed in terms of air changes per hour. For air motion, fans and exhaust fans are used. Fans should be chosen based on the area to be ventilated and not on the size

of the room alone. They should be uniformly distributed for proper .ventilation. The following table can be used as a thumb rule, but precise ventilation requirements should be calculated based on the activity performed in the room or building. Table 5.1. Fans for rooms of different sizes

Source: Central Building Research Institute, India. Note: Room length & width and fan sizes are in meters. B. Ventilation with ducts While designing ducts for air, number of features should be incorporated. The duct should be smooth. The number of changes of directions of the duct should be minimised. Branches from main ducts should be made with a gradual curve and should not be sharp. Galvanised mild steel is the most widely used duct material. This may be pressed into rectangular sections and bolted or riveted. Circular ducts can also be made with wrapped flat sheets. As the size of;the duct increases, there is a possibility of the wall vibrating due to the air movement. Efficient delivery of air to rooni spaces involves detailed calculation oeair flow velocities. At the points of delivery, the cross sectional profile of the duct may become smaller. Conical diffusers are best for efficient throw of air into the space. Dampers within the ducts will control the flow of air and resists spread of fire. Ventilation ducts may extend to all areas of a building creating potential routes for noise transfer. Proper care should be taken to contain it. 3. RECOMMENDED FRESH AIR SUPPLY Recommended minimUm rates of fresh air supply to buildings for human habitation: , Table ~.2. Minimum Rates of Fresh AirSupply

Note:

Source: Bureau of Indian Standards, 1988. Air change per hour is the volume of outside air allowed into a room in one hour compared

with the volume of the room.

4. SIZE OF THE OPENINGS FOR NATURAL VENTILATION Normally fifteen to twenty percent of the floor area is taken for the openings like windows and ventilators to provide light and air. However, there is a scientific method of calculating the openings for permanent ventilation based on Bureau of Indian Standards, 1988. A.Openings of the size obtained by the following equation should be provided on wind facing wall and also on the opposite wall.

A Q

= Area

of openings provided on wall in m2.

= Desired

rate of air flow in m3lb. V = Prevailing outdoor wind speed in m/h. K = Co-efficient of flow, which can be taken as * 0.6 for wind perpendicular to the openings * 0.3 for wind incident at 45° to the openings * 0.025 for windows on one external wall only.

EXERCISE 1. What are the guidelines for good natural ventilation? 2. Describe the methods of mechanical ventilation? 3. How do you calculate the size of openings for good natural ventilation?

IN1ERIOR DESIGNS PRINCIPLES AND PRACftCE

30

C. Humidity The control of humidity in the air is very important. Dry air puts strain on the nasal vassages of the nose making them dry and irritating. To avoid this moisture is added to the heated' air. This process is called 'Humidification', and it is done d;11fingthe winter season. The moisture is extracted from the cOOled air during summer. This process is called 'Dehumidification'. Normal relative humidity should be between 40 to 60 percent in the air. The desirable relative humidity for human comfort is 40 to 50 percent during summer and 50 to 60 percent during winter. 3. PROCESS

OF AIR-CONDITIONING

Air is a mixture of various substances composed of gases like nitrogen, oxygen, heliuIIl etc., It can absorb moisture in the form of vapour. The amount of moistur~ it can absorb depends on air temperature. Apart from these, air can have suspension dust particles, bacteria etc., In summer air-conditioning involves air cooling, dehumidifying, air cleaning and air distribution. In winter the cycle involves .air heating, humidification, air cleaning and air distribution. Both these operations should be done for a whole year use in the case of composite air conditiorring, The following filters are used for air cleaning. A. Impingement

filters

.

The impurities in the air are trapped and retained in the filter element. The materials normally used are glass fibre, steel wool, bronze or copper wool etc.,

B. Dry strainer filters These fIlters have collecting surfaces made of cloth, felt, glass fibre etc., C. Electrostatic precipitators These fIlters remove dirt by electrically charging the particles and then attracting them on to a plate. D.l<\ir washers A fme spray of water in the inlet removes all wettable dirt.

E. SteriUsation of air

.

Some organisms are removed by air washing. In, this process ultraviolet light is used for sterilisation. This light is used on the air duct leading to the conditioned space.

F. Odour control , The earlier method is by diluting with outdoor air. The present method is to use chemiCaldeodarants to reduce odour. 4. AIR-CONDITIONING

UNDER INDIAN CLIMATIC

CONDITIONS

In India, authentic research is not available on this subject. However, comfort zone for hUIllan activity can be presumed as 25°C to 30°C temperature and 45 to' 60 percent relative humidity. For health reasons, ror-conditioned spaces which are ftequently used by people, should have entrance lobbies where th~ temperatures are kept midway between exterior and interior spaces to avoid sudden changC of atmosphere. All structural elements used in the buildings like

floors, roofs and walls should offer enough resistance to the transmission of heat from outside. 5. TYPES OF AIR-CONDITIONING METHODS A. The foUowing cycle is involved in air-conditioning of any system (a) Sucking the outside air through a fIltering media. (b) Heating Of cooling the air. (c) Humidifying the air while heating is needed, and dehumidifying the air whil.e cooling is needed. (d) The air is passed through ducts for circulation to the designed spaces.

.

1. Cleaning of air 2. Cooling or heating of air 3. Humidification or Dehumidification of air 4. Circulation of air tllfOUgh ducts 5. AC space 6. Foul air taken out by exhaust faDs 7. Mixing of outside and used air

B. The followingtenns

are cODimonly used in air-conditioning

systems:

(a) Dry bulb temperature - The temperature of air recorded by an ordiqary thermometer. . (b) Wet bulb temperature - The temperature of air recorded by a thermometer whose bulb is covered with a wetted wick and exposed to a current of rapidly moving air. . (c) Dew point temperature - The temperature at which condensation of moisture begins when air is cooled. (d) Relative humidity - The ratio of actual water vapour pressure of the air to the saturated water vapour pressure of the air at the same temperature. C. Complete air-conditioning is used where the temperature systems: (a) Centralised system (b) Self-contained or packaged system

(a) Centralised system

- In this.system.

and humidity are controlled by a mechanical

system; There are basically two types of

all the equipment for air-conditioning is installed at one place and the conditioned air is distributed tllfough

ducts. The necessary equipment is assembled on the spot than in the factory. The entire space to be air-conditioned is divided into different areas. The temperature and humidity can be adjusted according to the specific requirements of each area. This system is economical because one system serves . many rooms than each room having a self-contained unit. (b) Self-contained or packaged system - A self-contained system comes with complete equipment of compressor, condenser, evaporator, fan, ftlter and

controls. Smaller units are kept within the room and larger units are placed at a different place and connected by ducts. This system is designed for application in smaller establishments like shops, restaurants etc., Room air-conditioJ1ers are small self-contained units. Most of them are air-cooled units to be placed on a window sill or near a source of outside air. Some of them are available for winter heating also. These units are self-contained . and the conditioned air is formed inside the unit and directly opened into the room without any help of ducts. Sometimes a combination of the two systems is preferred. The choice of a particular system depends on several factors like size of the structure, heating and cooling requirement, spa
32

IN1ERlORDESIGNS

PRINCIPLES AND PRACfICE

6. REFRIGERATION METHODS Summer air-conditioning needs the use of cooling medium, so it requires some artificial method of cooling. The major refrigeration methods used for .

air-conditioningare:

A. Mechanical vapour compression system B. Vapour absorption system A. Mechanical vapour compression system / Any liquid requires heat to be transformed into its gas or vapour state. Generally, if the pressure is increased then the transformation also increases quickly. The refrigerants normally used for cooling are Freon 11, 12 & 22 and in some cases ammonia is also used. The refrigerant at a pressure and temperature can be made to evaporate by allowing it expand to a lower pressure with the help of a throttle. It will have to absorb heat from the surroundings . to become a vapour. Through compression the heat is rejected. This principle is used in the vapour <;ornpressionsystem. B. Vapour absorption

system

In this process, the refrigerant used is water. Water absorbs heat while boiling. The evaporation is absorbed by a solution of lithium bromide. The weak lithium bromide solution is pumped into a generator where steam heats the solution. This heating bOils the lithium bromide solution giving away the water.

Thus the water vapour co~g

out of the generator is cooled by the condell';er. This principle is used in the vapour absorption system.

.

Most commonly used equipment in refrigeration and air-conditioning system are compressors, evaporators, condensers, cooling towers, spray ponds, expansion valves, air handling units and dUCl-;.Air-conditioning has become a specialised area requiring the services of a specialist for design, particularly for large spaces like cinema theatres, auditoriums, hospitals etc., For an interior designer it is essential to know the various units and arrangements iil air-conditioning so that proper care is taken in designing the interiors for air-conditioning. i 7. CALCULATION OF PACKAGED SYSTEMS The air-conditioning equipment should have the capacity to maintain comfort conditions inside Ii room with minim~ energy consumption. In deciding the type of system for cooling, there arc many factors which should be taken into consideration like number of windows, occupants, floor level, building orientation etc., However the package systems available in the market arc made of standard capacities. The following. table is meant for average climatic

conditions prevailing in India. The following table should be taken only as a thumb rule for calculation. Table 6.1. Capacity of systems for cooling

EXERCISE 1. 2. 3. 4.

What are Describe What are What are

the atmospheric conditions required for human comfort? . ' . the process of air-conditioning? the different methods of air-conditioning? the refrigeration methods ?

What is the need for air-conditioning?

Natural lighting is the light available in nature. We perform all our activities in this daylight. Daylight is nothing but sunlight on earth. Intensity of sunlight varies depending upon the atmospheric conditions. Sunlight is very bright in the morning and dull in the evening. Its brightness is more in the afternoon causing glare, and we try to protect our eyes with a shade from this glare. When we construct buildings we try to make use of this daylight to perform our activities inside a sheltered space. The availability of the daylight within a building will not be the same as it is outside because of the roof and walls of the structure. The admission of daylight into the building depends upon the number of openings provided in the building. If the building -isopen on all thefour sides then the daylight is not cut-off by any obstruction, but such a situation is uncommon in the densely populated areas 'Qfthe city. In India, it is preferable to use as much daylight as possible to save energy. However, it is not possible on many occasions to provide totaldaylight'inside the building. On such occasions, a combination of artificial and natural lighting is preferable. This will help to save energy without sacrificing lighting requirements. .It is difficult to measure the availability of daylight inside a building, but certain factors can be taken into consideration to measure it. 1. DAYLIGHT

FACTOR

The daylight received inside a building is measured as "the ratio of illumination at the working place inside a room to the total light available outside". This is called as 'Daylight Factor (DF)', which is expressed in percentage. The daylight factor includes the following: (a) Sky component (SC) - light received from the sky excluding direct sunlight. (b) t.xternal reflected component (ERC) -light received from exterior reflecting surfaces. , (c) Internal reflected component (IRC) -light received from internal reflecting surfaces. .

Thus the daylight available inside a building is only filtered and reflected sunlight. The value of sky Component (SC) is zero, when there is a complete roof over a building. It receives only ERC & IRe. Light coloured surfaces have high reflection factor and dark coloured surfaces have low reflectioh factor. The other parameters essential in interior daylighting design are outdoor atmospheric conditions. room size & shape. internal finishes, external obstructions & finishes and openings like windows & ventilators.

3. CALCULATION

OF THE OPENINGS

FOR NA~

LIGHTING

The amount of daylight needed for perfonning an activitJ can be derived from the above table. The required number of openings can be derived from the Fig. 7.1. The following assumptions are made, forcalcu1ating the openings for natural lighting in the Fig. 7.1. (a) Window areas are fo~ metal sasbes with usual dirt collection on glass. (b) For windows with wooden sashes. these areas sbould be increased by ten percent. (c) External reflected light is accounted. (d) The \;Vin49w areas are for room depths upto ten meters. (e) The windows should be located to have uniform spread of light. if) Sill level should be 1.0 to 1.2 meters. (g) The height of window should be 1.2 m or more. (h) External shading means sunsl;wJes or similar other shades. (i) ':l1e graph gives window areas for lS6lated buildings only. \\i\.'r. ;tdji)ining huildings are QUite high and obstruct the light. the values should be increased as given below. !{;llio = Distance between the buildings I Height of the obstructing building

4. GUIDELINES FOR GOOD NATURAL LIGHTING (a) (b) (c) (d) (e)

The interior surfaces of the walls should be painted with bright colours to reflect more light. The ceiling of a room should be, preferably, painted in white colour to reflect more light. The corners of a roomcan be provided with windows to avoid dark corners. Broad openings give better distribution of light Deep openings niinimise giare.

.

if) Diffused glass gives more light than plain glass. (g) Two opposite side openings give uniformity of light (h) Windows should be provided with sunshades or OChershading devices to eliminate glare of sunlight. (i) Metal window sashes admit more light than wooden frames. (j) Ventilators, at roof level, can be judiciously used to bring more light. EXERCISE 1. What is daylight factor? 2. What are the guidelines for good natUralligbting ?

Artificial lighting is necessary duIing the nights and also when natural lighting is poor. Mo~t of the interiors today are incomplete without artificial lighting. Wide variety of lamps are used to enhance the design and appearance. There are many interior spaces without sufficient daylight and almost dark in many cases. Under such conditions, an Interior Designer is compelled to resort to artificial lighting. Apart from this, artificial lighting has become a fancy. o .

INTERIOR DESIGNS P~INCIPLES

38

AND PRAcrICE

1. DIFFERENT TYPES OF LIGHTING ARRANGEMENTS The most important fact to. be remembered in praviding artificial lighting is that there shauld be sufficient light where an activity is performed. Keeping this in mind, different types af lighting arrangements are dis(''1lssed belaw: A. Direct lighting In direct lighting the SQurce af lighting is exposed 1bere are different types of direct lighting apart from direct exposure of the bulb.. They are: (a) Angular fitting. (b) Down lighter (c) Eyeball fitting (d) Track lighting (e) Shade lighting (a) Angular fitting - In this type af lighting. the light can be turned and pointed in any directian. It is a comfortable type af lighting because the light is actually directed towards the activity like reading or writing. The light is not directed towards the eyes, so. the strain an the eyes is eliminated. (b) Down lighter - The saurce af lighting is concealed in the ceiling. Even though the sources of light is nat seen, the light is projected dawnwards wherever it is needed to. perform an activity. Down lighters are useful for reading and othef'activities perf armed at a fixed place ina room. (c) Eyeball fitting - This is similar to dOwnlighter but it is possible to direct the light in any directian. It can light up dark areas of a room as it can be

directed. It has greater flexibility and occupies less space. (d) Track lighting - Track lighting is very popular. If it is used with discretion, it is very effective and dramatic..A simple track is wired and fitted on the .

wall or the ceiling accarding to. the need of the user. The track is usually four feet lang and can take faurlights, which need not be af the same type. Variaus types af lamps can be attached to the track at any point and directed towards the required side. Spotlights can be used to illuminate a painting or to get a special effect. (e) Shade lighting - This is very simpleand ordinarylightingfaund in our houses.It can be fixed to.a wall ar hangedat a law levelaver a table.The light saurce is covered by a shade. It is f'txed and cannat be maved or directed towards any place. Sametimes it is anlvnossible to. raise ar lawer the . shade. B. Indirect lighting Indirect lighting is more flexible and less harsh than direct lighting but it gives less light. Some light is last because it is reflected from a surface. Lot depends an the nature af that surface. The reflector can be a wall ar part of the fitting. The colour and texture af the reflector will affect the quantity and quality af light emitted. These type of f'tttings are good for general lighting and nat for warking. It can be used in the rooms af a house where general lighting is needed for relaxing. Saftness and brightness can be achieved by reflecting the light from a wallar ceiling. C. Diffused lighting In this type of fittings, light is emitted through a diffuser such as glass, plastic and fabric. The shade gives the form af light. The quantity and quality af tight depends on the sharle. They can be made to appear modem or ald. Old glass oil lamps and chandeliers are aften used as diffused glass shades. Fabric shades can also be used. D. Composite

lighting

In camposite lighting several types af lighting are used. In the living room of a house saft relaxing indirect lighting is needed but at the same time it may require direct lighting for reading or working. The f'tttings like angular lamps and dawn lighters can be used fram electric sackets far such activities. E. Concealed lighting In cancealed lighting the fittings are hidden so that only light is seen. This is dane with the help af fluarescent strips or spats or fIaads. When these are hidden behind a pelmet ar baffle, they can give good effect The curtain pelmet hides the strip light. Light is thrown an the material giving it a rich look. The pasitioning of such concealed f'tttings is very important otherwise they may nat give the desired effect.

39

ARTIFICIAL LIGHTING

2. VARIETY OF LAMPS Electricity for lighting is supplied through national grid at high voltages. These are reduced by step-down transformers at sub- stations. These are further brought down by local transformers. Bulk of the artificial lighting generated is alternating current (AC). Alternating means that the current flow direction is constantly reversing at the rate of 50 times per second. A single phase supply is most commonly used for residential consumers. Industrial and commercial consumers may take the three phase supply. In three phase supplies a fuse or circuit breaker is fitted to each phase. Electric lighting is distributed through .

lamps. Lamps can be divided into three categories: (6) General utility lamps are designed to give effective and economical illumination. (b) Special lamps give directional lighting. (c) Decorative lamps are meant for beauty rather than to provide light to perform an activity.

A. Incandescent lamps

.

These are also known as tungsten lamps, which are most commonly used in homes. They consist of a thin filament of tungsten inside a glass bulb. When current is passed, heat is produced and the temperature of the filament rises. The filament is designed in such a way that it reaches a temperature generating light energy and heat, which means that the filament glows or it is incandescent, so the lamp is known as incandescent lamp. These type of lamps cannot give a daylight colour. (See Fig. 8.1.1). B. Tungsten halogen lamps In a normal incandescent lamp the filament loses. material by evaporation. The inert gas inside the bulb reduces the rate of evaporation but it cannot prevent completely. Improvement can be obtained by adding halogen to the gas giving rise to a reversable chemical reaction. Tungsten evaporates from the filament and diffuses towards the bulb wall. This makes it necessary for the filament to be at a higher temperature than in an ordinary tungsten lamp and the bulb should be smaller. It has longer life and a higher light output than an ordinary tungsten lamp. It is useful for floodlighting and . lighting of film and TV studios. It is most widely used in automobile headlamps.. C. Fluorescent

lamps

The fluorescent lamp depends on the discharge of a current through a gas or a vapour at a low pressure. A fluorescent lamp consists of a long glass tube containing a mixture of mercury vapour and argon gas at a pressure. When the lamp is cold, the mercury is in the form of small globules on the surface of the tube. The argon gas is needed to start the discharge. The radiation emitted by the current discharge thr:mgh the mercury vapour is absorbed by the fluorescent coating which emits different radiation. Any colour may be used for the fluorescent coating. So many fluorescent materials are available to obtain almost any colour, including daylighL The circuit includes a starter and a choke to regulate the passage of current. Fluorescent lamps have a lower surface brightness and higher efficiency in terms of light energy. The production process is more difficult, so these tubes are more expensive. (See Fig. 8.1.2).

D. Mercury lamps Mercury lamps are discharge lamps which operate on the same principle as fluorescent lamps. At high pressure the radiation emitted by the mercury can be used without a fluorescent coating. The. radiation from the arc-tube is greenish white with some ultraviolet. It is converted into a visible red by a fluorescent coating on the inner surface, and the combined light from the arc tube and the coating has a colour which is considered acceptable for street, factory and warehouse lighting. (See Fig. 8.1.3). E. Sodium vapour lamps Sodium vapour lamps are similar to mercury lamps, but sodium is used for filling instead of mercury. The discharge which starts in the neon is of red colour. This warms the tube and gradually vapourises the sodium. After nearly twenty minutes. the sodium is fully vapourised and gives its characteristic yellow colour. The sodium discharge lamp is the most efficient means of converting electric.al energy into light. High pressure sodium lamps give a sunny yellow light. These are used for street lighting, flood lighting and factories & warehouses lighting. High pressure sodium lamps have avery high efficiency and long life. Two types of sodium vapour lamps are shown in the figure (See Fig. 8.1.4).

ARTIFICIAL LIGHTING

41

F. Metal halide lamps The colour of a mercury lamp can be improved by the addition of another metal. This can be achieved by using the metal in the form of its halide salt. The general design of metal halide lamps is similar to that of mercury lamps. These lamps may have clear glass or fluorescent coating. These lamps have a better colour rendering than incandescent lamps. They are mostly used for official and commercial purposes. G. Cold cathode lamps These lamps are used for illumination of cinema theatres and other commercial purposes like advertising. The advantage of cold cathode lamps is their long life. It also maintains better ,output during its life and starts instantly. Its 'life is not reduced by frequent switching. Like ordinary fluorescent tubes, it is available in wide variety of colours. The length of cold cathode tubes makes them suitable for bending into different shapes like letters, symbols etc., This makes them useful for decorative effects. Many colours can be obtained by the, use of different types of glass, which may be coloured or fluorescent coated. The first used gas was neon and 'Neon light' is a popular name for all advertisement lighting. Proper care should be taken in its installation and maintenance to avoid the risk of fire. H; FliCker All lamps, except the incandescent lamps, described so far go on and off 100 times in a second while working. This is too rapid a flicker to be noticeable to the eye. However the flickering is possible with twin lamp luminaires. Theluminaire is made with one choke for each lamp but with only one capacitor. The two lamp currents are neither in step nor out of phase, and they go on and off at different instants. They are often required for factories and workshops.

I. Emergency lights Many buildings prefer to have some form of emergency lighting if the electric supply to the ordinary lights fail. Electric lighting for emergency use can be provided if the building has a stand by generator The distribution should be arranged in such a way that only a part with few lights within the building is fed by the generator. There is no need for full lighting under emergency conditions, and lightiIlg in the main corridors and staircases is sufficient. Emergency lighting is very important fQr hospitals. Some offices, cinema theatres, schools and residentialtJatsalso need emergency lighting. i EmergencylightiIi1g can also be provided by abattery system. These lights are sWitch~d on only when the mains fail and cannot be used while elettric supply is avaihible. They are not iJltended to give full illumination, but sufficient lighHorpeople to perform their activities. These lights work on low voltage DC current and fed from a' battery. -Atrickle charger permanently connected to the mains ensure that the battery is always fully charged. Thus as long as the main supply is healthy the battery'l(ghting circuit is, kept open, but immediately once ti1emaifiSfail the relay contacts close and the emergency lights come on. There .arebattery chargers and relays made for this work. The charger muSt be\,pe~ntly Switched on and con~ins the relays necessary to stop the , . . charging current when the. battery is, at full charge. . There is anp~er method of emergency lighting which makes use of speciall1.l111inait~~;vi~ich contain its own battery, charger and relay. It effectively houses a complete low voltage system to operate one light. They are made in a variety()f s~~ees. and sizes; They may give incandescent or fluorescent light. These self contained luminilires are sealed for life and need no maintenance, exceptbattery~~~ging. 3. LIGHTING

ACCESSORIES

The electricity services in a building consists of light switches, power points and simifarot)Ier outlets. Such fittings are known as accessories, because , they are accessory to tl)e wiring. The way these acce.s'sories appear and function is very impot1;uit for the user. ' A. Switches " A/switch is used to make or interrupt a circuit. A light switch consists of three p~. They are.the box, a front plate and the mechanism. Standard boxes for recessing within a wall are 35 mm deep. The shallow boxes are 25 mm deep, WhIChcan be used over the surface of the wall. The older type of switch mechanism was dolly operated. At present, dolly operated switches have been superseded byr9Cker operated switches. The advantages of the rocker switch are that it is/easy to operate and it is almost not possible to hold it half open. Most manu~acturer~make switches in two standard capacities of 15 to 20 amps and 5 amps. When the switch is wired and inserted in the box it ne~ds a front plate over It. AS~ltch with a separate front plate is called a grid switch. When the front plateJs made as part of the switch, then it is called plate switch. T() isolate power eqUipment, it is often desirable to use a double pole switch. This

\

,

expression indicates a switch which opens live and neutral circuits, and two contacts work side by side. This is normally used for heaters, fridges etc., They are made in 15, 20, 30,45 and 60 amps. (See Fig. 8.2.1). B. Sockets A socket outlet is popularly known as a power point. The arrangement of socket outlet is similar to switches. It consists a box to house th~ outlet, ,the outlet hole and a front plate. Plugs and sockets rated at 2 and 5 amps are available in both two and three pin versions, but 15 amps are available only with three pins. Two of the three pins are for the live and neutral wires, and the third one is for a separate earth wire. Sockets are available without Sw~tches. Unswitched sockets have contacts permanently connected to the wiring and the appliance to be connected is turned on as soon as the plugi,s inserted and turned off, when the plug is taken out. If a switch is incorporated in the socket outlet the switch must be put on before the line becomes connected to the supply. A further improvement to the socket outlet is the addition of an indicator light which shows when the socket is switched on. Like switches, sOCket outlets can be recessed into a wall or they can be mounted on the surface of the wall. (See Fig. 8.2.2, 8.2.3 & 8.2.4).

C. Fused connection units These units are used for connecting a single permanently fixed appliance to the wiring. They perform the same function like a socket and plug combination. The difference is that the two parts cannot be separated as plug and socket. They are similar to/socket outlets and connected to the wi'fingin the same way. The difference is the fuse connection which is accessable for replacement from the front. Like socket outlets, fused connecting units can be switched or unswitched, and they can be with or without a neon light indicator. (See Fig. 8.2.5). D. Boxes When wiring is done by pulling cable through conduit, access must be provided into the conduit for pulling the cable inside, and also where the paths of cables branch into two or more conduits must be connected together. The type of box used is the same as that used for housing switches. Boxes 'are aVMlable for r~cessing in walls or fixing to the surface of walls. The boxes have a number of circles on them for the electrician to remove anyone of them to make a hole in the box to accept standard electrical conduit. In addition to rectangular boxes, circular boxes are also made for general conduit work and terminating wiring at points to take light fittings. When boxes are used for joining conduits, they are covered with a blank plate. (See Fig. 8.2.6). E. TV outlets Today many houses and flats have a television, which may require connection to an outdoor aerial. It is becoming iQcreasingly common td provide a common aerial system serving all the flats of an estate. It avoids the ugliness of large number of aerials and also one jxJwerfu~ aerial erected in a pr@perly chosen position can give better reception. Thus it becomes necessary to run a television aerial cable from the aerial to an outle'. A television needs power supply, soan ordinary socket outlet is provided near the aerial outlet. (See Fig. 8.2.8). F. Lamp-holders In public buildings, the light fittings are fixed as part of the electrical installation. In houses and flats..lamp-shade or fitting is left to the owner, after occupation. Plain lamp-holders are provided to fit in ordinary 100 and 150 watts, tungsten bulbs. They usually have a ring to which. a lamp-shade or similar other fitting can be attached. The top of the lamp-holder screws down to grip the flexible wire 'cord on which it is suspended from. the ceiling. The insulated wire on which the lamp-holder is suspended performs two functions. It carries the current to the lamp and supports the wp-ight of the holders, lamp and shade. Lamp-holders have protective shields to prevent accidental contact and dampness. (See Fig. 8.2.7). G. Ceiling roses At the ceiling the wiring should be connected to'the flexible wire. This connection is made by means of a ceiling rose. It consists of a circular housing with a terminable block inside and an opening on the underside for the, flexible cable to come out of o,e rose. Where main wiring is inside the ceiling, this wiring enters the rose through the back or top of the rose. Where the main wiring runs exposed on the sutfaceof the ceiling, it enters the rose through a hole in the side of the rose. Ceiling roses are made with either two or three live terminals in addition to an earth terminal. (See Fig. 8.2.10).

H. Pattresses . When a wiring system is installed on the surface of walls and ceilings where there is an off-set in the surface which the wirmg cannot follow then it has to be supported off the surface. Then it becomes necessary for some sort of distance piece to take up the gap between the fitting and the surface behind it. These are known as 'pattresses'. The inclusion of the pattress makes it possible for the cables, to enter the socket outlet from the back, otherwise there , woUld be an untidy junction of the cOnduit with the bottom of the socket outlet. "" '

4. PROTECTION DEVICES

,

,

Electricity is dangerous and it should be handled with care, otherwise it may lead to accidents. Tne general principle of protection is that a faulty circuit should be cut off from the supply and isolated until the fault is de~ected and repaired. The two dangers that are to be prevented are' fire and shock to ,the ~ people. They arise from three kinds of faults. They are short circuit, overloading and a fatilt to earth. Tne devices commonly used to overcome these faults are described below: '

A. Rewirable fuses The most commonly used protective device consists of a thin fuse wire held between terminals in, a porcelain or bakelite holder., It is inserted ill the circuit and the size of fuse wire is matched to the rating of the circuit. The fuse is designed in such a way that if the current exceeds the rated current of the

circuitthe fuse wire blowsand disconnectsthe circuit.(SeeFig. 8.3.1). B. Cartridge

'

fuses"

' ' The rewirable fuse has limited controlling capacity, so the cartridge fuse was developed. The fuse wire is mounted oetween two end caps which form the terminals of the complete fuse link. The wire is surrounded by a closely packed granular filler and closed in a solid casing. When the wire melts or blows-; the energy is absorbed by the granular filler. These fuses are also known as High Rupturing 3.PROTECTION DEVICES Capacity (HRC) or High Breaking Capacity (HBC) fuses. '

C. Miniature

CirCuit Breaker (MCB)

An alternative to' a wire when overheated is a circuit breaker. MCB has a rating similar to that of a fuse. When an overload occurs, the magnetic pull of the coil surrounding the tube increases and the slug moves through the tube. The speed of travel depends on the magnetic force arid on the size of the current.As the slug approaches the other end of the tube the air gaps in the magnetic circuit are reduced and the magnetic force is increased until it is great enough to trip the circuit breaker. With this mechanism the time taken to trip is inversely proportional to the magnitude of the overload. The MCB has a toggle switch for operation. It is possible to dispense with a bank of switches if a distribution board with MCB's is placed. (See Fig. 8.3.2).' D. 'Residual Current

Circuit Breaker (RCCB)

Fig. 8.3.

2. MCB

This is a circuit breaker which detects a current leaking to earth and uses this leakage currentto operate the tripping mechanism. The leakage current is a residual current and so the name of the device is Residual Current Circuit Breaker (RCCB). There are two types, current operated RCCB and voltage operated RCCB. The primary function of both is to give protection against shock. E. Circuit capacity protection There is no need to be worried about voltage drop, but high voltage current passage should be guarded. The cable must be rated at a little more than the current actually taken by the circuit. It is very important that every cable in a pennanent installation in a building must be protected. Atevery point where a smaller cable branches from a larger one there must be a protective device to safeguard the smaller cable. This is provided by the use of switchgear and

distribution boards, where a main divides into two or more s'ubmains, and the submain divides into a number of fmal circuits. Ideally, the protective devices should be graded so that the smaller fuse opens before the larger fuse when any fault occurs.

F. ~rth protection The normal protection to avoid direct contact of people is the provision of insulation on all current carrying wires. Indirect contact with exposed metal parts of an appliance due to any fault will cau.sea shock. Protection is provided if the wiring is earthed. The household appliance should be preferably double insulated. Proper care should also be taken in using portable electrical appliances in factories and workshops. :S. CALCULATION OF ARTIFICIAL LIGHTING REQUIREMENT A. The folIo~ing factors should be considered in choosing the lighting appliances.

(a) Lighting effiCiencyof the luminaire.

.

(b) Type of luminaire used. (c) The interior surfaces and their reflecting capacity. (d) Mounting height of luminaires and their spacing on the walls. (e). Periodic dirt collection on the luminaires and the interior suifaces. B.Recommended levels of illumination

Light given by a source or received by a surface is measured in lumen. Lumen refers to the luminous flux or light flow emitted within one solid angle by a point source having a uniform intensity. The density of luminous flux upon a surface is measured in lumen per square metre or lux: The unit of luminous, intensity is ~~I.~edas 'candela'. ' .~..---

D. Guidelines for lighting design (a) Fluorescent lamps are more efficient than incandescent lamps. Fluorescent lamps produce 50 to 60 lumens per watt, whereas incandescent lamp's produce 10 to 17 lumens per watl. The life of a fluorescent lamp is four times longer than the incandescent lamp. (b) Luminaires should be located at a height of minimum 2.1 m. above the floor level, except for some special reasons. (c) The normal reflectance may be assumed for ceiling (white) 'as 0.7. walls (off-white) as 0.5 and floor (grey) as 0.3.

(d) Location of light points should be on the longer walls.

.

.

(e) Periodic cleaning of luminaires ,is necessary to keep up their efficiency. if) Interior surfaces should be painted with bright colours for good surface reflection. (g) General illumination in a room should satisfy the brightness ratio of I: 10. Tj'Ie most important activity performed should be considered for deciding . toe illumination.' (h) The number of light points should be decided based on the floor area space and the importance of the activity performed. For example, in residences single point is sufficient upto 12 sq. m. and two light points are required for floor area upto 22 sq. m. .

.

(i) Glare of a luminaire can be reduced by dimming or by using baffles, iouvers or diffusers.

E. The lumen method of lighting design The lumen method of design is the most widely used for the determination of lighting layout for providing illumination on the working plane from overhead lamps in a regular pattern. The formula used is

N

= Number

of lamps

E = Lux on working'plane A

= Floorarea

(sq. m)

= Lumens per lamp U = Utilisation factor F

,

M = Maintenance factor

Example: An office 10 m x 5 m requires an illumination level of 300 lux on the working plane. It is proposed to use 40 w. fluorescent fittings having a rated output of 2440 lumens each. Assuming a utilisation factor of 0.5 and a maintenance factor of 0.8, design the lighting scheme. Here

= Lux on working plane = 300 = Floor area = 10 m X 5 m F = Lumens per lamp = 2440 U = Utilisation factor = 0.5

E A

M Now, using the formula

= Maintenance

factor

= 0.8

A. Wiring process The wiring process consists of choosing a suitable type of cable giving adequate protection and putting it into the building. The wiring should be durable, safe and good in appearance. All conductors should run along the walls and near the ceiling for easy access ability of inspection and repair. There are two types of wiring used at present for safety and security. They are conduit wiring and concealed conduit wiring. In conduit wiring, the wires are run in steel or PVC conduits for protection from injury or fire. In concealed conduit wiring, the conduits are concealed in the ceiling or walls for appearance. Any joints should be made through junction boxes for easy inspection. A wiring diagram should be prepared before installation indicating clearly the main switchboard, mains and sub-mains, points and their control. (See Fig. 8.4).

Fig. 8.4. Graphical Symbols of Electrical Diagrams

Source: Intcrnational Electrotechnical

Cominission Docliment, 617.

B. Residence wiring diagram The following factors are taken into consideration in the preparation of the residence wiring diagram (See Fig. 8.5). (a) First. the interior furniture layout is decided based on the activity to be performed. (b) Then. the light points are decided depending upon the activity to be performed h each room.

(c) The wiring length is minimised as far as possible.

.

(d) The wiring is assumed to be concealed in the RCC slab with pvc tubes. (e) Details of the light points to be provided in given below: .

.

EXERCISE 1. Describe different types of lighting aJTangem:nt" ? 2. Describe various types of lamps used for lighting in buiJdings ?

3. What are the differentaccessoriesusedin lighting?

.

4. What are tl.e different types of protection devices used in artificial lighting ? 5. How do you calculate the artificial lighting requirement?

..J Scientific study of sound is known as 'AC9usticS'. All human beings live with sound by birth. It is a medium of communication, which includes speech and music. Unwanted: sound can be damaging like any other form of pollution. In interior design good hearing of sound is essential in auditoriums, theaters, schools, assembly halls and board rooms. The general requirements for good acoustics are: Even distribution of sound. * Proper reverberationtlme of the sound. * Absence of unsuitable reflections like echoes. * Acceptable level of background noise. * Sound is absorbed by tbe air, wall surfaces, furniture, furnishings and people. Ooodacoustic conditions in an enclosed space are achieved when the sound rises to'the required intensity in all parts of an enclosed space without any echoes or distortions .and dies down quickly to allow succeeding sounds to follow. 1. PROPERTIES OF SoUND Sound is caused by a vibrating body. Sound requires a medium for transmission. This medium can be a solid, liquid or gas. In the creation OI SUWIUill me air, the air molecules vibrate from a vibrating body and the ear drum is able to recognise the. vibrations. Vibration of the air particles at the ear drum with a definite frequency and amplitude gives reception of sound near the ear. The air pressure rises ttbove atmospheric pressure and then sinks below it near the ear

51

ACOUSTICS

with as much frequency as the vibrating particles. These air particles create vibration known as simple harmonic motion. Sound cannot be transmitted in vaccum as vibrating particles are necessary for sound transmission. .".......

A. Sound waves . Sound is transmitted through air in the form cf waves moving at about 340 meters per second at ordinary temperatures. These. waves move from their I sOUrcein

all directions at equal speed forming the 'wave front' in the shape of a sphere. This sphere expands to the limits of an !inclosed sp~ce. Thus the

space is filled with rapidly moving spherical sound wave fronts. These sound wave fronts strike the walls, floor and ceiling, and then reflect; in various .

directions. The reflected sound waves create spherical wave fronts until they again strike the boundaries of the enclosure. This process of reflection continues until all the energy of vibration imparted to the original waves has been absorbed and the sound dies away. B. Wavelengths Wave motion means the ability to transfer sound from one place to another. All wave motions can be described in terms of wavelength, frequency and velocity. Wavelength is the distance between any two repeating points on a wave. It is measured in ,meters. .

C. Frequency Frequency::; the rate at which sound waves vibrate. It is measured in 'hertz (l1z)' as vibration cycles per second. If any object or surface vibrates 100 times per second then the frequency of the sound waves produced will be 100 Hz. Human hearing interprets frequency as pitch, which is heard as 'low' or 'high'. The human hearing system responds to frequency range from 20 Hz to 20,000 Hz. D. Velocity -" The wave. front of sound travels from its source with a steady velocity irrespective of the frequency. For example, high pitched notes travel at the same speed as low pitched notes. The velocity of sound is affected by properties of the material it travels. The velocity of sound in air increases as the temperature or the humidity increases but it is not affected by weather variations. Sound travels faster in.liquids and solids than air because the densities and elasticities of those materials are greater than air. The velocity of sound is measured as the distance moved per second in a particular direction. It is measured as meters per second.

E. Resonance Every object has a natural frequency at which it will vibrate when disturbed. For example, the sound created by a metal bar or a block of wood when dropped on the floor. Resonance occurs when the natural frequency of an object coincides with the frequency of any vibrations applied to the object. F. Strength of sound .'. The strength of sound depends upon its energy content. The amplitude of the sound wave is the property that is known as loudness. The maximum displacement of each air particle takes place in the case of loud sound. To measure the strength of a sound, it is necessary to measure its power, intensity and

pressure.

..

G. Sound levels The decibel measurement of sound is formed by th~ ratio between the measured sound and the threshold of hearing. Jbe term 'sound level' implies that the standard value of the threshold of hearing is used. The threshold of hearing is the weakest sound that average human ear can detect. The threshold of pain is the strongest sound that the human ear can tolerate. The smallest change that the ear can detect is about I dB, but a 3 dB change is the smallest difference normally considered significant. A 10 dB increase ordecreliSe makes a sound seem twice as loud. H. Loudness Loud may be a common word but it has a firm technical meaning. The sensation of loudness in human hearing is the reception by the ear and interpretation by the brain. Loudness of a particular sound depends on the amplitude of the sound wave and also the frequency of the sound. Human hearing is not equally sensitive at all frequencies. The human ear is most sensitive in the frequency range between 2 kHz and 5 kHz and least sensitive at low frequencies or at extremely high frequencies.

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

52

I. Noise Noise is the term used for any unwanted sound. In rural life sounds rarely become noisy because they provide a sense of participation in the community life, and they hardly ever reach intolerable lev~ls. Th!s is because the village life is slow and linked with natural surroundings. Rapid urbanisation increased noise sources like industry, traffic, radio etc., They also brought change in social attitudes. In a village one knows source of sound and conveys some meaningful information, whereas a city is full of noises which often cannot be tolerated. The low density of rural areas with longer distance between noise sources and listener reduces disturbance. In high density cities the distances between sources and listeners are comparatively less creating nuisance. 2. SOUND IN INTERIORS Outside sound cannot be controlled unless the source and the receiver are controlled, but sound produced in an enclosed space can be controlled with sound absorbents. There is a need to know the behaviour of sound in an enclosed space. The reflection, echo and reverberation of sound should be properly designed for good hearing in an interior. A. Sound reflection When sound is reflected it obeys the Jaw of reflection of all waves. The angle is measured between the path of the sound wave and reflector. The angle ofreflection on concave surfaces concentrates sound waves in certain areas, on convex surfaces disperses sound waves and on parallel smooth surfaces sound waves move as they do from the source of sound.

B. Echoes An echo is a long delayed reflection. When a reflected sound wave reaches the ear and immediately another sound wave follows it as a repetition. If the reflection is delayed and also strong then the echoes blur and confuse the original sound. Thus echo occurs if a strong reflection is received later thap 1/20th ~f a second after reception of the direct sound, then the reflecting surfaces are situated at a longer distance than 15 meters. Echo occurs, when the shape of tbe reflected surface is curved and smooth. To overcome echoes, there.-:5 ,,'oleed to choose proper shape of the room and its surfaces, and use suitable sound absorbent materials internally to disperse echoes.

C. Reverberation Reverberation is the cQntinuance of sound after the source of sound has stopped. When sound is produced in an enclosed space, it continues to be heard until all the energy imparted to the original sound waves has been expanded. The reflected waves travel in all directions in the room losing a certain amount of energy at each reflection until the sound dies away. If the room has carpet, curtains and furniture, then these soft materials absorb the energy rapidly killing the sound quickly. If the room is empty, the reflections continue for longer time and the period of reverberation is long. Incorrect reverberation is the most commonly observed acoustic defect. ' D. Reverberation time With instruments it is difficult to decide when the reverberant sou~d has died away, so a drop of one millionth in power (60 dB) is used. Re~rberation time is defined as the time taken fot a sound to decay by tiO dB from its original level. The time taken for decay depends on the distance between the surfaces of the room, the absorption of those surfaces and the frequency of the sound.

E. Ideal reverberation time The optimum reverberation time depends on the volume of the rpom and the types of sound created. Sabines formula is found to give reasonable predictions of reverberation time for rooms without excessive absorptidn. The formula uses a knowledge of the surface areas of the room and their absorption characteristics to predict the reverberation time for those conditions. '

RT

= Reverberation

time. of the room (m3) Length x Width x Height. A = Total absorption of room surfaces (m2 sabins) i.e.. sum total of (each area x absorption coefficient for that area)

V

= Volume

3. SOUND ABSORPTION For icontrolling the sound in interiors, there is a need to have the desired reverberation time. To achieve this reverberation .time.. it is necessary touse sound absorbent materials on the wall, floor and. ceiling surfaces. Before adopting any sound absorbent material for use, it is necessary to know the coefficient of absorption and other desirable qualities of the material.

A. Coefficient of sound absorption When considering the sound absorbing power of the various building materials, a definite basis of comparison is necessary. An unobstructep open window may be regarded as absorbing all the sound energy that reaches it. Hence if the opening of one meter square window has a coefficient of absorption as one, the absorbing capacity of all other materials is compared with this. Thus, if the absorption coefficient of a material is 0.5, it means that the material is

54

INTERIOR DESIGNS PRINCIPLES AND PRACfICE

capable of absorbing 50% of the sound, when compared to 100% of an open window of one meter square. A perfect absorber would have an absorption coefficient of 1.0 and, a poor absorber has an absorption coefficient near zero.

B. Sound absorbent materials Buildin,g materials have different capacities of absorbing sound. In general, hard and dense substances absorb less sound, whereas soft and porous

materials have good absorption capacity. A hard surface reflects the sound. Soft and porous materials reflect less sound and permit the sound waves to ,

penetrate into their pores. Curtains, carpets, clothes and upholstery absorb sound and affect the reverberation period of a room. Structural materials like brick, wood, metal, plaster and glass have small absorption capacity, so special materials are developed for use in interiors. The absorption capacity of most

materials is not the same at all the frequencies. It is usually high for sounds of medium pitch and becomes less as the pitch increases or decreases. The lnterior designer must design to have the requisite aco'lstic qualities without excessive use of special materials. The sound absorbent materials can be 'broadly classified into four categories: (a) Porous materials (b) Cavity resonators (c) Resonant panels (d) Composite type materials (a) Porous materials

-

These are soft materials

with pores inside. When sound waves strike these pores the pressure

forces air particles

into the narrow

pores. Thus the so~d energy is considerably reduced. The surfaces of such material increases its absorption. They are normally used to absorb high sound frequencies. Some of the porous sound absorbent materials are glass wool, curtain, rock wool, fibre boards and other soft furnishings. (b) Cavity resoTflltors - Cavity resonators consists of a container with a small opening, where absorption takes place by the resonance of the air. Cavity resonators can be designed to absorb sound of any frequency. These cavity resonators are adopted for sound absorption of a particular frequency. (c) Resonant panels - These panels act as sound absorbents and also as building panels. In these panels there is a gap between the absorbent material fixed to the board and the wall background or any backing. Porous materials can be used in the gap to increase sound absorption. These panels are nonnally used to absorb low sound frequencies. (d) Composite type materials - These sound absorbents have all the three qualities described above. They consist of perforated panel over a gap containing porous absorbent. These panels may be made of metal, plywood, hard board and plaster board. The performations in the panel allow the ,porous material to absorb high sound frequencies. The porous material should be placed near the perforated panel for maximum efficiency. These type of sound absorbents are widely used now because they can withstand different sound frequencies, easy for installation and economical. C. Desirable quaUties of acoustic materials Good acoustic materials should have the following qualities: (a).It should have good sound absorbent coefficient. (b) It should have uniform resonance on different sound frequencies. (c) It should have uniform sound absorption on different sound frequencies. (d) It must have good structural strength. (e) It should have good fife resistant capacity. if) It should be termite resistant. (g) It should withstand heat and moisture. (h) It should be durable and economical. (i) It should be easy to handle for working. (j) It should have decorative appearance.

'

Source: Central Building Research Institute, India. ... NRC is the average of the absorption coefficients at four test frequencies of 250, 500, 1000 and 2000 Hz. Concept developed by CBRI..

4. ACOUSTIC DESIGN OF A HALL Example: Calculate the total absorption units required in a hall based on thefollowing assumptions. * Capacity of the hall ... 500 persons

... 2500 cubic meters * Area of the hall (V) ... 0.8 seconds * Required reverberation time (RT) Ans. (a) Total absorption units required can be obtained based on Sabinesp,formula _rrr

I'\... ,.

.

=

Total absorption units required 500 units (square meters) (b) If 2I3rd hall is full with 333 persons with 0.46 absorption units per person, then the occupants provide 333 x 0.46 = 153 units. (c) Out of the total required absorption units of 500 units, 153 units should be deducted. (d) The balance of 347 units should be provided with the help of sound absorbent materiais on the walls, flooring and ceiling. So acoustical design for 347 (square meters) sabins should be done. 5. GUIDELINES FOR GOOD ACOUSTICAL DESIGN (a) In constructing a building for good acoustical design, the SUITOundingareas should be quiet without noise emitting-sources like busy traffic, railway tracks, industries and commercial establishments. (b) The volume of an enclosed space is very important for good design, particularly the height of the structure. (c) The shape of a room or hall should be properly chosen because they affect the reflection 01 sound waves. For example, fan shape plan is suitable for

theaters and auditoriums.

.

(d) The ceiling and walls of an enclosed space should provide favourable sound reflections. Concave shaped ceilings should be avoided because they create echoes and unfavourable sound reflections. For example, the ceiling of an auditorium should have an upward slope towards the back side. (e) The depth beneath the balcony of an auditorium or theater should not be too great, otherwise hearing will be bad in the back seats. if) Optimum reverberation time should be taken into consideration while designing. (g) In an auditorium or theater, audience and seats contribute a lot to sound absorption. The absorption coefficient for seated person is 0.46 square meter

sabins. The absorption coefficient for empty seats is, for plain seat 0.02 and cushion seat 0.15 square meter sabins.

.

(h) Most of the sound absorbing materials are fibrous or porous in nature, Some of the locally available low-sound absorbing materials are sutH, banh, woOOwool, chattai etc.,

EXERCISE 1. 2. 3. 4. 5.

What What What What What

are the properties of sound? is 'Reverberation' ? How do you calculate 'Ideal reverberation time' ? is Co-efficient of sound absorption? are the different categories of sound absorption materials? are the guidelines for good acoustical design?

1. DAMPNESS PROTECTION A. Reasons for dampness in buildings The dampness in buildings is mainly due to improper structural design and poor workmanship during construction. Some of the reasons for the dampness

in buildings are:

.

(a) When the buildings are constructed in water logged areas and the subsoil of the building gives access to water. I

58

INTERIORDESIGNSPRINCIPLESANDPRACTICE (b) Poor wall and roof joints allow nun water seepage. (c) During excessive cold weather conditions, moisture is deposited on the walls and roof. (d) Poor workmanship during construction like laying improper slopes for disposal of rain water, gaps in roof and wall joints, poor pipe joints etc.

The dampness in buildings create unhealthy living conditions, breaking and cracking of walls and roofs, crumbling of plaster, peeling of paint, growth ot fungus, corrosion of steel in RCC construction, damage to wood and electrical work, and breeds termites. B. Preyentive methods There are several preventive methods to stop the dampness in buildings. The materials normally u~ed for DPC (Damp Proof Course) are bitumen, plastic sheets, stone slabs, slates, tiles, bricks, cement and lime concrete etc., DPC provided in buildings can be classified into the following levels: (a) Foundations - Where the foundations are not properly drained like water logged areas, the structure should be detached from the face of the excavated ground. A trench of 30 cm width should be made all-round the structure upto the bottom of the foundation. The trench should be filled with coke, gravel or stone. Open jointed pipes may be provided at the bottom Of the trench to drain out the water into a nearby drain. (See Fig. 10.1). (b) Basements - To maintain dryness, the entire structure below ground level should be provided DPC. This can be done by spreading a layer of DPC, like bitumen, over the entire area of the floor and continuing the same through the external walls vertically up to the roof. This process should be done i~ a dry season. (See Fig. 10.2). (c) Floors- In dry areas, normally a filling of dry coarse sand under the flooring is sufficient. In another method, stones are laid without voids and rammed sufficiently without consolidating. If there is a possibility of moisture entering the floor, it will be necessary to have a DPC, like asphalt layer, before a concrete floor is laid. (d) Walls - Vertical DPC for walls is already discussed under besements. The horizontal DPC, like bitumen, in external walls should be provided atleast 15 cm. above the ground level. Cavity walls also contain dampness because two parallel walls of masonry are separated by a cavity. As there is no contact between external and internal walls except at wall ties, the water penetration is reduced. The wall ties should be made of water-moof

(i) In one process, * lime concrete is laid to the required slope, * then two coats of bitumen are applied over dried lime concrete. (ii) In another process * hot bitumen is laid, * then a layer of coarse sand is spread on it, * then lime concrete of 10 cm. thick is laid to proper slope, * finally, two courses of flat tiles are laid in cement mortar. (iii) Mud plaster terracing with tiles is good for hot and arid places like the interior areas of India. In this process, * hot bitumen is laid first, * then a layer of coarse sand is spread on it, * on this mud phuska layer is laid and covered with mud-gobri mortar, * finally, flat tiles are laid in cement mortar.

C. Curative methods Dampness is generally insignificant if it is not visible. If dampness is detected, it must be assumed that it may be due to the penetration of rain water or moisture or water absorbed from the soil. Some of the common defects, their causes and curative methods are discussed below: (a) Rising dampness in walls - It is visible as d;unpness at the base of both external and internal sides of the walls and flooring. It may be due to the water absorbed by capillary action into the base of th\( wall from the ground and spreading further. This occurs normally due to the lack of an effective damp proof course. To overcome such defects, ope should be introduced in the basement at an appropriate level after underpinning 'the walls. (b) Penetration of rain water - It is visible by uniform dampness of external walls only. It may be due to thin wall construction or poor workmanship or inadequate protection from rain. To overcome such defects, there should be sufficient wall thickness or using cavity wall constructiop. or the exposed surface~of the walls should be protected with cement plaster. (c) Leakage of roof at gutters or down pipes - It is visible in patches at the top of walls or on the ceiling. It may be due to improper placemeht of gutters and downpipes. To overcome such defects, there should be sufficient gutters laid to a slope and properly placed down pipes to take out the rain water.

The joints between the roof, gutters and down pipes should be carefully done.

.

(d) Condensation below flat roofs - It is visible as uniform dampness on ceilings. It may be dueto inadequate gutters an<Jdownpipes or broken roof tiles or rain water stagnation. To overcome such defects, there should be adequate gutters and down pipes laid to proper slo~s or proper laying of DPC and roof tiles or filling cement grout (mixture of cement, sand & water) into the cracks and joints of the roof. . . (e) Salt deposits during construction - It is visible as uniform dampness on all walls. It maybe due t<;> the use of marine sand or bricks containing sulphates. To overcome such defects, marine sand or bricks or salty water should not be used during the construction. (/) Growth of fungus -. It is visible as green slippery surface or small plants with cracks on the walls. It may be due to water stagnation or leakage. Normally such fungus growth is seen near toilet or rain water pipe junctions, where the joints are loose allowing the flow of sewage and dirty water. To overcome. such defects, the surface should be cleaned thoroughly of fungus and leakages of all kinds should be plugged. Periodical checking pf such surfaces avoids further growth of fungus. Care should be taken to dispose the rain water on the roof, sunshades, porticos and walls. Apart from providingDPC ,n appropriate levels, proper care should be taken during. construction for rain water disposal measures. There are many water proof chemicals available in the market to prevent and cure dampness in the buildings. Now-a-days these chemicals are widely used to work against dampness.

60

INTERIOR DESIGNS PRINCIPLES AND PRACfICE

2. TERMITE PROTECTION A. Termite attack sources It is not easy to eradicate termites established in buildings. Controlling termites during the building construction is the only way to-prevent termite damage. The eradication of soil-born termites in buildings is discussed below because most of the termite damage in buildings in India is due to soil-born termites. They live in moisturise
methods

To eradicate termites successfully, there is a.need to assess the infestation. Termite treatment of the entire building is better than treating only at places of infestation. Curative methods can be divided basically into four methods: (a) Building repairs (b) Treatment of nests (c) Treatment below the flooring (d) Treatment of galleries (a) Building repairs - The first step is to fmd out the points of entry of termites in the building. Building repairs may be made to break the direct contact between the soil and the wood in the building. Wooden frames of doors and cupboards going into the flooring should be removed and set on top of the flooring: In the case of wooden flooring, the floor should be separated from the soil. If timber beams and rafters or any other timber structural members are damaged by termites, they should be replaced or treated with a preservative. Painting, brushing or spraying of chemicals will be only a

temporary solution.

.

(b) Treatment of nests - There is a need to destroy the termite nest, where they are born, to eradicate termites totally from the building. Any termite mound around the infested building withiri a radius of 50 meters should be opened and destroyed by pouring chemicals inside. The quantity of chemicals to be used depends on the size of the nest. All wooden articles around the infested building should be examined for signs of terniite attack. If any signs are found, they should be dug out and the nest treated with chemicals. After destroying the nest, a soil barrier should be created around

~~~.'

.

(c) Treatment below the flooring:'" The destruction is very difficult, if the termites nest is concealed in the basement or benea.th the concrete floor. In such cases, termites can be eradicated by poisoning the soil under the floQr. This process is normally carried out by digging holes vertically through the floor and injecting the chemicals. In another method, holes may be drilled through the foundation walls from outside and the chemicals are pumped below the floQring. Chemicals should also be injected into the cracks and expansion joints of the flooring. The holes and cracks should be

properlysealedwithcondreteafterthe treatment. (d)

'

Treatment of galleries ..;::'In the case of light termite attack, the destruction of these galleries is enough to protect the building. Such galleries are found around wood work, cupboards, electrical wiring etc., These galleries make it easy for poisoning the nest of the termites. A small hole is made in each" gallery and chemicals are blown into the gallery. Then it is covered with wet clay.

The anti-termite eradicating treatment usually lasts for several years, bUflmonthly inspection should be carried out to prevent recurrence. In the event of recurrence of attack, preventive treatments should be immediately undertaken. All chemicals used in these anti-termite treatments are poisonous to human beings and animals. They should be handled and used with care. Hand gloves, gumboots and respirators should be used. Anti-termite treatment of buildings is a specialised work and there are 'Pest Control' organisations offering these services. 3. FIRE PROTECTION A. Causes of fire There may be several reasons for the cause of fire. Fire in urban areas should be dealt with care, when compared to rural areas. Some of the major causes . .

of tire are:

(a) Increasing concentration of population and activities in the cities may lead to an Qutbreak of fire in buildings in del1<;elypopulated areas affecting .

surroundingbuildingscausingloss of lives and property.

(b) The increasing use of wide range of domestic electrical appliances, air-conditioning systems, synthetic and plumbing materials are also responsible for. many fire accidents. (c) Negligence of fire safety measures in industries is also a major cause for fire accidents. .

.

A building cannot be made fire-proof because there is no building material which is totally fire-proof. The building can only be made fire-resistant by using firc-resistant materials. (a) Materials in relation to fire are of two types. They are combustible and non-combustible materials. Combustible materials not only bum themselves but also increase the intensity and growth of fire. Non-combustible materials do not contribute to the growth of fire but get damaged. Some of the commonly used fire-resistant building materials are bricks, clay products, concrete, asbestos cement, glass, cement and gypsum plaster. (b) The building should be planned in such a way that the construction materials should withstand the fire for a considerable time. It is necessary to isolate various parts of a building to minimise the spread of. fire. (c) Sufficient spacing and separation from the adjoining buildings should be kept. (d) All the structural elements of the building like /loors, walls, columns, beams etc., should be made of fire-resistant materials to protect people, goods and other contents within the building. (e) Fi,re-escape routes like staircases, corridors, halls and lobbies should be constructed with fire-resistant materials and separated from rest of the 'building.

(j) (g) (h) (i)

.'

.

Suitable means of escape should be provided for the people to leave the building safely and quickly at the time of fire. In multi-storeyed buildings suitable equipment should be provided for detecting, extinguishing and warning of fire. In the case of industrial buildings, high risk areas should be isolated from others. Any city area is demarcated into distinct zones based on the fire hazardness of the buildings.

C. Fire-resisting

construction

The severity of a fire depends upon the amount, nature and distribution of combustible material in a building. The choice of non-combustible materials for construction is essential. (a) Bricks can stand exposure to fire for a considerable length of time, so brick masonry is most suitable for fire-resistant cop.struction. (b) In framed construction, RCC frames are preferable to steel frames for construction. (c) Fire-resistance increases with the thickness of a wall and also walls should be plastered with cement or gypsum plaster. ~d) TImber partitions should be covered with some fire-resistant materials to withstand fire. (e) RCC /lOOrs and roofs are suitable for fire-resistan\ construction. The floor should be given suitable slope for easy draining of water while fighting . . .. fire.

(f) Ceilings should be made of fire-resistant materials like fibre-glass, asbestos cement boards etc., (g) Door and window openings should be kept to a minimum. Fire- resistant doors can be made by covering the wooden doors with iron sheets on both

sides.

.

(h) Doors and windows are the only means of fire escape. They should be specially treated and provided with such fittings that are not affected by heat. They should be made of fire-resistant materials. (i) In multi-storeyed buildings, the stairs and lifts are the only means of escape. The walls of stairs and lifts should be made of fire-resistant materials. (j) Concealed wiring system is recommended because the wires run in steel or PVC tubes providing protection from the risk of fire. (k) For air-conditioning of buildings, the chilled water system is preferable to direct expansion system. (I) Highly fire-prone or hazardous areas should be isolated and specially treated with fire-doors, which automatically close and give fire-alarm.

(m) Modem smoke sensors or gadgets may be pennanently installed in buildings for early detection. (n) (0) (p) (q)

.

A separate water sump or underground tank with a pump that starts automatically in case of fire should be provided. A public address system in the building will help communication with people on different floors, which help to guide them in case of a fire. Fire-alarm systems should be installed to give warning to the occupants of a building. These can be manual or automatic. Fire-extinguishing arrangements should be provided on the basis of the importance of the building. Some of the fire fighting equipments are carbon dioxide, water and sand used in various forms.

EXERCISE 1. What 2. What 3. What 4. What

is dampness'? Describe the preventive and curative methods? are the sources of tennite attack? Describe the preventive and curative methods? are the causes of fire? What are the preventive mea'lures ? are the various measures to be taken for fire resisting construction?

Interior surfaces of abuilding which need treatment and design are ceiling, walls, doors & windows and flooring. Apart from interior furniture, some natural features can be brought inside the building like indoor plants and flowers. Thus the following interior parts need special attention arid designing. .

1. Ceiling

2. Walls

3. Doors & Windows 5. Furniture

4. Flooring 6. Decorative items

1. CEILING Ceiling can be painted or treated with false or suspended ceiling. While painting it should be kept in mind that ceiling is the best light reflector. Light colours reflect more light than dark colours, so judicious use of shades must be made while painting the ceiling. Suspended ceiling is normally used for acoustics' or decorative purposes. It is normally seen in cinema theatres. auditoriums, board rooms and ratio & TV stations where sound control is needed. The finishing material to be used for the suspended ceiling depends on the acoustic properties of the material. They are normally used as panels or boards for

IN1ERIOR DESIGNS PRINCIPLES AND PRACfICE

64

easy casting and fixing. Suspended ceiling is also used for decorative purposes. If the height of the interior should be reduced. then suspended ceiling is used. It helps to change the proportion and atmosphere of the interior. Suspended ceiling can conceal the air-conditioning ducts and electrical wiring. Thus it helps in creating an artificial atmoiJphere of the designers choice.

2.-WALLS Walls play very important role in interior designing. The treatment of walls can be divided into: A. Painting B. Wall paper C. Panelling D. Cadding E. Glass F. Fabrics A. Painting There are wide variety of paints available in the market. Painting of walls should take care of the activities to be performed in an interior. Depending on the use of the interior space, light or dark shade paints can be used. Sometimes all the four walls need not look alike. One of the walls can be fixed with a glass or mirror or wall paper. B. Wall paper Wall papers are preferred because of wide variety of designs and colours creating an illusionary impression. -The designs should not be tOobold or pale. . Scenic wall papers look good on long walls. It is preferable to use wall papers on unbroken walls without doors and windows. so that the total impact of the visual design is felt while entering the room. If the wall paper is used on all the four walls. then the texture and pattern should be carefully chosen. The" problem with wall papers is that they gather dust and get dirty easily. so they require frequent cleaning and replacement depending on the use and maintenance of the interior.

C. Panelling Panelling is done for acoustics or decorative purposes. There are various types of materials used for panelling like wood. plywood. block board etc.. If the wall finishes are pale. panelling can change the look of the walls without painting. Panelling can help to improve the appearance of the interior. The type of material to be used for panelling depends on the activity to be performed. In theatres and auditoriums. materials with good acoustic properties should be used. Any decorative material can be used for decorative panelling.

D. Cladding Wall cladding is done for easy cleaning and maintenance. Cladding can be done with tiles or metals. Ceramic tiles are durable for wall covering of to~lets and kitchen. Marble and other tiles are used in recent times for decoration and easy maintenance. Metals like aluminium, copper and stainless steel are also used for cladding because they are hard. easy to clean and decorative. The choice of tile or metal cladding depends on the use of the interior.

E. Glass Glass is used sometimes to cover an entire wall for strategic views and natural light. Mirrored glass is also used to give spacious look to small interiors. Normally glass is used upto the door level only. The use of glass gives an elegant look to the interiors.

F. Fabrics Fabrics may cover one or two walls of a room. They can be hung by nailing them at the ceiling level. There are wide range of fabrics which can be directly hung on the walls. Some of the good fabric materials are given below: Satin is a soft shining material. * Plastic is washable without wrinkles. * * Taffeta is a crisp shining material with plain weave. * Gingham is a cotton material with plain weavein stripes and checks.

* Gabardine is a fumly woven material in plain colours. * Damask is a woven material with patterns on both sides. * Brocade is a fabric woven on a loom with design on the right side only. * Velvet is a pile weave silken material, but collects dust. Nylon is also good material for interior use. * Organdy is a cotton material which retains its crispness. * The choice of fabric to be used depends on the use of the interior and its appearance. 3. DOORS & W1NDOWS

Doors and windows in an interior should be treated with harmonious effect. They occupy quite a lot of wall area providing access, light and view. . Curtains and blinds are normally used for doors and windows. Recently, glass is also extensively used. There are three main functions of curtains and blinds: appearance, privacy, heat and light control. The colour, style, pattern and texture of curtains and blinds should be related to the interior scheme as a whole. A larger curtain or blind can give the illusion of a larger door or windpw.They are also used for privacy. Heavy weight curtains and blinds are useful in controlling light and heat from outside. It also cuts glare.

A. Curtains Some of the decorative treatments of curtains for windows is given below. They may be used for doors also depending on the need. (a) TIe-back curtains are designed to be pulled to the side and held by decorative tie, sleeve or cord. (b) Pelmets spacingat the top of th~ curtain give}}
B.BlindsThere are many types of blinds in operation. Some of the well known types are Festoon, Roller, Roman, Venetian and Vemcallouvre. Most blinds can be fitted either to the window opening or to the wall above the window opening. 4. FLOORING There are various types of flooring. The following are some of the commonly used f1()Oritigsurfac~sin the interiors:

A. Stoneflooring C. TIledflooring E. Glass flooring G. Cork flooring I. Carpetflooring

B. Marbleflooring D. Timberflooring F. Lino'leumflooring H. Plasticor PVCflooring

A. Stone flooring Stone flooring consists of thin slabs laid on concrete bedding. The slabs may be normally square or rectangle in sftape. The stone slabs are fixed with thin layer of mortar. when the stone slabs are' properly set, mortar in the joints is taken out and flushed with floor surface. Stone flooring is hard, durable, easy to lay and maintain. B. Marble flooring Marble flooring is normally used for superior type of floor construction. The construction of this flooring is same as stone flooring except the use of

marble pieces instead of stone pieces. This type of flooring is decorati e in iJ.~arance but needs periodic cleaning and maintenance. C. Tiled flooring liles are made in mosaic or cement mortar or clay in square, rectangle and various other shapes, sizes and thicknesses. The method of laying a tiled

,

flooring is similar to stone flooringbut more care and skill are required.It is decorative,durable,easy to lay but becomesslipperywhen it is wet. The . flooringalso dependson the type of tilesused. D. Timber flooring limber flooring'is used for dancing halls and auditoriums. In timber floors, the prevention of dampness is very imPortant. limber floors consists of boarding supported on timber joists, which are nailed to the wall plates at their ends. In case of large spans, intermediate dwarf walls are constructed to support the joists. limber floors are used only for special purposes. E. Glass flooring Glass flooring can be used 'JOf special occasions to tr:msmit light from an upper floor to a lower floorlike ground floor to basement floor. In glass flooring, the structural glass in the form of tiles and blocks is fixed within frames of various types. The structural glass is available in different forms and thicknesses. The framework containing glass blocks should be closely spaced so that the glass flooring can safely take the load F. Linoleum flooring LinoleuIIl is a covering. It is laid on wQOden or concrete floors to improve their durability and appearance. It is available in rolls of various colours and designs. Linoieumtiles are also available. Linoleum covering is either laid loose or laid with an adhesive on dry. and smooth floor surface. On Wooden floors, they are nailed at the ends. It is attractive, economical, easy to wash and clean but does not offer resistance against fire and dampness.

G. Cork flooring

.

Natural cork is the outer bark of the cork oak tree. It is used in the form of tiles and carpets like linoleum flooring. Cork tiles are usually made in two qualities, ordinary and heavy density. It provides noiseless, non-slippery and resilient flooring. It has good heat insulation properties. '

H. Plastic or PVC flooring The plastic or PVC flooring is a recent development in floor construction and used as covering over the concert floor in all types of buildings. PVC (poly-vinyl-chloride) is fabricated in the form of tiles and available in different sizes in varying colour shades. The plastic flooring is laid in the similar way as tiled flooring. Though plastic tiles are hard and durable, they are slippery. It is not advisable to use plastic.4iles on wooden flooring because the cost of fixing is expensive. I. Carpet flooring ,

Carpet flooring gives comfort and appearance to an interior. Carpets absorb noise. They create an impression of luxury and establishes a colour scheme. Carpets can be wall-to-wall or scatter rug type. It depends on the condition of the floor and the need. Rugs can be easily handled and cleaned. They can be

shifted to different rooms. Scatter rugs are used near furniture groupings for uniformity. Wall-to-wall carpets create the impression of large room. They can be cut to fit irregularities in floors. They hide inexpensive floors an~ worn out floors in old houses. Wall-to-wall carpet creates unity in interior design. Durability of a carpet depends on the quality of fibres used. Most commonly used carpet fibres are acrylic, nylon, polyester, polypropylene, viscose, rayon and wool. Wool is considered to be the best kind of fibre for carpets because it is durable and colour-fast. Cotton rugs are soft and crushable. They are not colour-fast and soil easily, but they are durable. Jute and hemp are used for making the backs of carpets and rugs. Most important factor for durability of carpet is the height and closeness of pile. Medium colour shades are more durable. The floor should be made smooth before laying the carpet. If the carpets are to be joined, they should be sewn together or joined with adhesive tape. Carpets can be laid loose or bonded to the floor with adhesives or fixed by using grippers. While choosing any carpet for flooring, the factors to be taken into consideration are soiling, dimensional stability, colour fastness, fire-resistance, wear-resistance, sound & thermal insulation and resilience.

A. Upholstery Upholstery consistS 'Ofthe cushioning and covering of an item of furniture. The essential need of upholstery is: (a) to achieve additional comfort by providing cushioning material. It should be soft and made of suitable material and shape;

(b) to improve the appearance of the furniture.

" ,

Traditionally, fibrous materials like horsehair or coconut fibre were used for stuffings. Now-a-days, latex and polyurethane forms are uSt}~.it~m~~~J:UoRing. '

Latex foams are durable and resilient, but expensive in comparison with polyurethene foams. polyurethene is the most widely used materiaUdr Cushioning due to its low-cost and easy handling and fabncation. ,. .' . ,(; ~":;;" ~:.., .

'" '.-,.'

B.Partitions

v.~, ,. .",'"' :

A partition is a wall within a building which divides tIle inner space into roQms or areas. Usually load-bearing and permanent non-loadJ,~~.,gpartitions are constructed on site, whereas movable partitions are prefabricated and assembled on the site. Movable partitions are used where the wa~ls,IK.~J~~quently !

opened up to form one large floor area. Sliding partitions are used as series of panels which slide in tracks fixed to the floor .and ceiling. Structufat.:stability is-

!, essential to all partitions. Partitions may be required to offer sound insulation, fire resistance, design flexibility and provision for electric~,s~fym~~<:".:

C. Build-in furniture

:','

.

.,.:-

-: c'-':~

yt'

'

'ro:-'

Built-in furniture is widely used in the interiors. It can be made in RCC or any other material like wood, plywood, etc., The advantage of built-in cupboards and wardrobes is that they can be made during the construction of the building. Thus the inieriorand exterior can be' planned together. Most of the , built-in furniture seen in modem interiors is mass-produced in a factory. Wide variety of such built-in furniture systems are, available for fixing in residences, offices and commercial establish~ents. The main reasons for their popularity are: standard design, low-cost and easy construction. "

6. DECORATIVE

ITEMS,

.

,', "

.

In designing an interior, small itemsJ.yvery important role...These objects need not be costly but they lend beauty, identity and stt~~gth to an interior, '., , Each pi~ce should be related to its surroundings. Some of the commonly used decorative items are given below: A. Plants B. Rowers

C. Paintings

E. Pictures A. Plants ,

D. Sculptures '

, '

"

'

Interior landscaping, has become a specialised job because plants add beauty and purpose to an interior. Plants separate different areas by acting as

physical barriers. The selection of plant material should be based upon the specific functions of the interior. Most of the plants are decorative in function. Every plant or group of plants in an interior has a different natural form. The most common plant shapes are round, oval; vertical, horizontal and dropping. Rounded forms create large plant masses for enclosures. It is best to use these forms for unification in the composition. Vertical forms add visual

height to a space. Horizontal forms add width. Dropping' forms tie vertical and horizontal forms together. Individual plant forms create different planting anangementsfor different interior effects. By combining various forms, interior desig.perwill have a greater range of landscape design. B. Flowers Modem flower arrangements make use of all forms of plant materials like leaves, twigs, tree trunks and stumps. Rose, lily, calendula, daisy, marigold and

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69

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

lotus are some of the flowers suitable for interiors. It is necessary to select a place for flower arrangement. There should be a clear plan for the flower arrangement expressing the mood and purpose, Then the flower material should be selected. The height of the arrangement should be related to the interior design. The real purpose of flower arrangement is to enhance the beauty of the interior. The flower arrangement should be in harmony with the colour scheme Of the room and the furnishings. The arrangement can be made with dried flowers, fruits, vegetables, artificial flowers etc.

C. Paintings

.

Paintings can be made ofoit and water colour. Oil paintings and water colour~ are equallyl effective. Their main difference is the textural effecf. An oil painting is usually on Canvas or board and not covered by glass whereas water coloUr is always framed and cavered with glass. The place to hang the painting should 6e chosen. It can be highlighted with spot lighting. Limited number of paintings should be used in a room. Too many small paintings on a wall or a room can spoil the interior. D. Sculptures Normally the materials used in sculptures are wood, clay, plastic and glass. Modem sculptors use old boxes, pipes, springs. and utensils tQ-make various shapes. The art of assembling is unlimited. A piece of sculpture is a wonderful object in an interior. Sculptures show nicely in blank spaces with clean and clear backgrounds. Neutral backgrounds suit sculptures. Small articles can be effectively displayed in groups in shelves. Sculptures should be compact and stylistic in design.

E. Pictures

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Pictures should be framed properly to make. their appearance more effective. Family photographs can also be framed and hung at proper places because they ll;md.personal identity to an. interior. Pictures can be .hung in all. kinds of interiors-like residences, offices and commercial establishments. Judicious selec~on and placement of pictures is necessary.

EXERCISE 1. 2. 3. 4. 5.

What are the What are the What are the Describe the What are the

various methods of treating wall surfaces in an interior? various interior design treatments of windows? different methods. of flooring? major items of interior furniture _? different decorative items used in an interior?

Painting is nonnally required for three surfaces. They are walls, metals and wooden surfaces. Wall surfaces chip & crack, metals rust & corrode and wooden surfaces get warped & scratched. Painting of these surfaces' is necessary to increase the beauty, strength and longevity. Different paints have' speCific . properties which prevent or delay the decay of these surfaces. These paints fonn a protective layer on the surface of the materiaL For interiors, most people want good paint finish, so manufacturers categorise paints according to the degree of paint shine. Paints without shine are called flat or matt paints and paints , with shine are called low-lustre, eggshell, silk or satin and gloss or high gloss finish." 1. INGREDIENTS OF PAINT Paint is a mixture of four important ingredients. They are pigments, additives, binders and' solvents. Pigments render colour and opacity to the paint. Additives give the paint special properties such as resistance to rust and fungus. Binders hold the paint together and binds it to the surface for durability.

Solvents enable brushing or rolling of paint on a surface.

.

.

.

.'.'"

2. TYPES OF PAINTS Depending on the solvent used, paints can be broadly classified into two categories. They are A. Water-based paints B. Oil-based paints A. Water-based

paints

In water~based paints, the contents are mixed with clean water only:Some of the water-based paints are discussed below. (0) Lime wash - Lime wash or colour w~h is based on lime, i,norganicalkali fast pigments and few other additives. White wash is a lime wash without pigment. The ingredients of lime wash are suspended in water prior to application. Glue, casein, salt, alum, drying oil and tallow are often used to .

. increase the longevity of lime wash. It is applied (or interior and exteriqr surfaces of the building. (b) Di~/emper - Distemper is superior to..l4me wash and available in wide range of colours. It'is available in the fonn of dry powder and paste. . Depending upon the binding material:/it may be washable or non-washable. It is economical even in new buildings which are not fully dried out. It .

is economically priced and durable. It is available as oil-,bolind and acrylic. Acrylic distemper is much better than oil-bound distemper in finish and durability. Non-washable distemper should always be removed before painting. Washable distemper can be painted with a similar distemper after dusting down. Oil-bound distemper is more expensive than non-washable distemper, but it provides washable paint film cover which can' be

repainted. It may be applied by brush or spray gun. Distemper is widely used in the interiors. (c) Emu/sion paints

- Emulsion

.

paint is used as a decorative finish. There are three major types of emulsion paints. They are polyvinyl acetate, styrene

and acrylic resin. Acrylic emulsions are also known as plastic paints. They have good adhesive properties, washable and easy to maintain. Premium emulsions are based on pure acrylic latex and high opacit~ pigments. Emulsion painr is thinned with water, easy to apply and dries rapidly within two hours. It has no odour and it is a good alkali resistant. It is durable artd washable. It is available irtmatt and gloss finishes. Emulsion paint should not be applied over distemper or colour wash. It may be applied over oil-bound distemper or oil-paint. Two coats of emulsion paint is necessary for longevity. These two coats should be applied on the same day: It may be applied by brush or spray gun. Emulsion paints are frequently used in

interiors. (d)

'

- Silicate

paint consists of a thin pasty suspension Of alkali resistant inorganic pigments and extenders. It is not damaged by alkali in cement. It is also porous to allow moisture to escape. It may be directly applied on brick, plaster and concrete surfaces after wetting. No primer coat is necessary. Two to three coats are normally applied. The painting tools should be cleaned with water immediately after use. Painting should be Silicate paints

avoided in hot weather. Silicate paints are mostly applied in the interiors.

'

(e) Cement paint - Cement paint consists of white cement, alkali fast pigment. accelerator and other additives. It is available as dry powder in several shades. It is economical, water-resistant and durable even on damp surfaces. Cement paint should not be used on smooth surfaces" gypsum plaster or lime wash. It is mQfe Qurable on rough surfaces. Cement paint surfaces can be repainted with any non~oil based paint. It is the most widely used external paint for buildings. B. Oil-based paints Unlike water':based paints, solvent-based paints need to be mixed with a solvent like turpentine or any thinner which is a petroleum by-product. The purpose of these solvents is to make the~pplication of coating easy. These Pilints are tough, durable and stain-r~sistant. They can withstand frequent cleaning without losing its shine. These paints can be used on all cement plastered surfaces, metals and wood. It forms a non-porous film, which ensures stain resistance;of the ,surface. We shall discuss below some of the oil-based paints. (a) Chlorinaiedrubber paints - It can be applied without a primer. It is water and algae resistant. It is also highly resistant to acids, alkalis and fire. It is non-toxic, easy to apply and dries rapidly. It is applied to clean rust-free metal, wood, concrete, asbestos, brickwork and insulation boards. It is used

in laboratories, factories, summing pools etc.'

,

,

(b) Oil-paints - There are many varieties of oil-paints. Oil-paints provide an impervious layer to water. Oil paint should always be protected by one or two coats of alkali resistant primer. Oil paint should not be applied during damp and humid weather conditions. Repainting on these surfaces should be done with oil paint only. Synthetic ertamel paints are the best for painting wooden and metal surfaces. Ort the wooden surfaces, the choice is between synthetic enamel with an opaque .finish or transparent finish to show the natural beauty of the wood grain. They are tough, durable and glossy in finish. They protect metals from corrosion. Synthetic enamels come in three categories of grade I, II and III. 3. THE PAINTING PROCESS The painting process varies depending upon the type Qf paint to be used and the surface. to be painted. Most of the paint catalogues give the instructiorts for painting. However basic steps in painting are: A. When painting an interior wall for the first time, allow a period of atleast 6 months after applying a coat of lime wash for thorough drying of cement plaster. Then remove lose particles or flakes and make the surface free of dust, dirt,grease etc., by using sand paper. B. If the existing wall is to be repainted, the previous coating of lime wash or distemper should be scraped off. In the case of an oil based paint remove the shine by sand paper. For wooden surfaces, the dust should be cleaned and made smooth by sandpaper. The metal surfaces should be dry and free from rust, grease, oil etc:, before painting. C. The first primer coat should be applied to provide adhesion between the paint film and the surface. It smoothens the surface to make it less absorbent and also il1creases the spreading capacity of the paint. Different primers are available for cement plastered surfaces, wood and metals. D. Then the putty is applied to fill minor cracks and surface imperfections. Major cracks and dents must be repaired with cement mortar or plaster of paris (POP). The drying time for putty is 5 to 6 hours. E. Then the second primer coat is applied to sandwich putty between two primer coats becausepai~ting()n putty leads to a patchy look. F. Finally, two coa.ts should be applied to get the desired finish and colour. Each coat should be toridly,dry before the next one is applied. Drying time for different paints depends upon their composition.

Normally for internal walls, distemper and emulsion paints are used; for external walls, cement and texturised paints are used; for metals,synthetic enamel paints are used; for wooden surfaces, synthetic enamels, melaminised and polyurcthene finishes are used. 4. COMMON PAINTING DEFECTS AND REMEDIES Some common painting defects and remedies are discussed below: A. Crqcking or chipping - It may be due to excessive use of putty~thick required quantities. .

coat of paint or defective surface. As a remedy, use the paint and putty in the

B. Effloresc,ence - It may be.due to the presence of saJts in the building materials like b*ks and cement mortar. As a remedy, give a time gap of6 months including one monsoon between plastering and painting of the surface. Try to use porous paints only. .

C. Blistering It may be due to the trapping of air, moisture or solvents between the paint film and the surf~ totally dry before painting and avoid painting under sunlight. . ... ~

As a remedy, allow the surface to be

D. Flaking - It may be due to improper application of primer coat over putty or shrinkage or expansion of the surface. As a remedy, do not leave gaps in covering putty with primer coat and also see that the surface is dean and dry. E. Patchy finish .""-It may be due to high paint absorbent nature .{)fthe surface. As a remedy, apply an extra coat of primer. F. Poor drying - It may be due to the humidity, poor air circulation, low-temperature or alkalinity of the surface. As. a remedy, try to reduce the impact of weather conditions as far as possible by cleaning the Surface with white spirit, then wash with soap and water: G. Poor. shine - It may be due to the poor surface preparation or pre$ence ofofl or thinning of paint. As a remedy; clean the surface thoroughly before painting as per the instructions of the manufacturer. H. Discolouration - It may be due to the exposure to sunlight or chemicals. As a remedy, use light-fast colours with chemical resistant finish or suitable

. pnmer.

EXERCISE

t.

What is the purpose of painting and what are the ingredients of paint? various types of paints uSed in the buildings. .

2. Describe

3; Describe tt)e basic painting process? 4. What are the common painting defects and remedies?

.

A. RuleS & Regulations I. The INDIAN INSTITU1E OF INTERIOR DESIGNERS is an organisation dedicated to the advancement of Interior Design profession in India and forthe establishment of good professional and trade practices and ethics among its members. 2. Indian Institute of Interior Designers is dedicated to highlighting and enhancing the image of the Interior Design profession not only in India but also foreign countries by exchanging know-how and news andviews'on the subject with similar organisation abroad. 3. The membership of IIID is open to Interior Designers, manufactures of materials used in interior, furniture makers, interior fUrQishing contractors and dealers of materials used in interior furnishing jobs. IIID brings the Interior designers on one hand and the manufacturers and dealers of inter~or furnishing products and materials, furniture makers and the interior fumishing contractors on other hand, on a common platform and thereby tends 'to enhance the art and image of the profession not only among the clients and the customers of Interior designers, and the executors of interior furnishing jobs, but also on a national level.

4. Indian Institute of Interior Designers is one of its kind and the only one in India. It has membership of over 1500 of all India basis.

.

(a) IIID provides services which will assist the Interior Designer in the practice of his I her profession and enhance the growing recognition of

Interior Design as a profession.

.

(b) IIID brings the Interior Designers, manufacturer of materials,fumiture makers and Interior furnishing Contractors on One platfonn and offers them an opportunity to interact, understand the new innovations and have up-to-date .information about the Trade and Interi()rDc,,~gning; (c) IIID will encourage the imparting of specialisededucation through eminent and distinguished interior designers to students Qptingfor Interior Design as career and with that object will PUOiUethe setting up of improved cour~es in Interior Design in educational institutions in the country. (d) IllD will help Lay down general conditions of contract and prepare standard forms of agreement for Interior FurnisJtingcontractors to include

escalation,. mode of measurement, defects, liability and arbitration.

.

(e) IllD will organise various competitions like 'Interior of the Year' yearly competition for the Interior Designers. 'Best Interior job of the Year' yearly competition for the Interior Furnishing Contractors and 'Best Product of the Year' yearly competition for the manufacturers, and give

suitableawards.

.

(j) IIID will organise seminars and exhibitions in India on works done by Interior Designers and of materials produced b¥ manufacturers. IIID will invite foreign. Interior Designers to participate in seminars, and foreign manufacturers of materials to exhibit thejr products in India so that similar products may be produced in the country. (g) IllD will give its members the privilege of using IllD appellatron the symbol of qualified professional Interior Designer, manufacturer of quality

products and a contracting firm bound by its Code of Ethics.

.

(h) IllD is planning to have Chapters at various places wherever they have minimum 20. Associate Members in order to promote the activities of the Institute.

.

72

INTERIOR DESIGN PRINCIPLES AND PRACTICE

Normally for internal walls, distemper and emulsion paints are used; for external walls, cem.ent and texturised paints are used; for metals, synthetic enamel paints are used; for wooden surfaces, synthetic enamels, melaminised and polyurcthene finishes are used. 4. COMMON PAINTING DEFECTS AND REMEDIES Some common painting defects and remedies are discussed below: A. Crqcking or chipping - It may be due to excessive use of putty~thick required quantities.

. coat of paint or defective surface..As a remedy, use the paint and putty iil the .

B. Efflorescf!nce - It may be due. to the presence of sa,lts inthe building materials like brictcs and cement mortar. As a remedy, give a time gap 0£6 months including one monsoon between plastering and painting of the surface. Try to use porous paints only. C. Blistering It may be due to the trapping of air, moisture or solvents between the paint film and the surface.. As a.remedy, allow the surface to be

totally dry before painting and avoid painting under sunlight.

.

D. Flaking - It may be due to improper application of primer coat over putty or shrinkage or expansion of the surface. As a remedy, do not leave gaps in covering putty with primer coat and also see that the surface is clean and dry. E. Patchy finish ...;". It may be due to high paint absorbent nature .-ofthe surface. As a remedy, apply an extra coat of primer. F. Poor drying - It may be due to the humidity, poor air circulation, low-temperature pr alkalinity of the surface. As a remedy, try to reduce the impact of weather conditions as far as possible by cleaning the surface with white spirit, then wash with soap .and water. O.Poor shine - It may be due to the poor surface preparation or presence of oil or thinning of paint. As a remedy; clean the surface thoroughly before painting as per the instructions of the manufacturer. H. Discolouration - It may be due to the exposure to sunlight or chemicals. As a remedy, use ligbt-fast colours with chemical resistant finish or suitable

~~ EXERCISE

1. What is the purpose of painting and what are the ingredients of paint? 2. Describe various types of paints USedin the buildings. 3; Describe the basic painting process? 4. What are the common painting defects and remedies?

.

INDIAN INSTITUTE OF INTERIOR

.74

DESIGNERS

(i) IIID has a long term planning to affiliate our institution with various other institutions in the world i.e. ASID Intern!i,tional Design institute, and also ensure that various professionals and trade members have an opportunity to participate in the various activities gojng on in the World concerning the members. ). IUD has various committees as under:

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(a) Membership Approval and Enrolment Committee This committee scrutinizes all the applications received and recommonds to the Managing Committee for approval of membership. (b) Newsletter and House Journal Committee This committee is responsible for issuing Newsletters at intervals and shall also be responsible to make journal whereby a lot of work. of Interior designers of India can be presented. (c) ExhibitionslSeminar Committee This will make arrangement to hold exhibitions and seminars from time to time and appraise the public and members about the development. of various new materials and trades. (d) Fund Raising Committee... It Will have a get together for members for public fellowship.

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Education Committee This committee will promote education and standardisethe

. same

for various institutions inlndia. This will also help the students to know more about the .

trade and practice new fields of interior designing. Code of Ethics and Professional Pr.ctices . Members of the Indian Institute ofInt~rior Designers (IllD) assure understanding among themselves and with their clients be subscribingw a.code of Ethics and professional Practices. The initials UD. .after and interior designer's name.means that he isa member of the Indian Institute of Interior !>(;signers, and. in becoming a member has agreed to observe the code. Failure to comply with the stipulations set forth in the code may result in disciplinary li(;tiOIl. A niember of I.I.D. has the oblig~"oJ1 to (a) .Confirm to thec:ode of Ethic~ap~.st~dardsgQverninghis profession in any state in which be practices, as well the U.D. Code. (b) Perform his ProfessiQnalservj~~with COtnpetence and integrity that will properly serve the best interest of his clients. (c) Exercise discretion and dignity in the use of his name and Ll.D. affiliation in advertising or pub1.icity.concerning products,. merchandise. of services

of any manufacturers of distrib~tor.

(d) Serve. the interests of his cIient.~d. the rights of those whose contra,ctshe administers. (e) Preserve confidential information derived from his client and not release information concerning his projects witllout the consent of his dient. (f)Se.ekeveryopportunity to advance the dignity and prestige of all of the design disciplines. (g) Maintain satisfactory credit standing as an obligation to his profession and to his community. (h) Refrain from making any statement that unjustifiably injures the reputation. of another designer. (i) Encourage qualified young people to study interior design; assist those entering the field; and maintain a programme of selt~impr01ement and . . education for himself. (j) Contribute to the exchange and advancement of technical information within his own field and the allied professions dealing with the art md science of environmental design. .

Membership Qualifications MEMBERSHIP of the Institute will be granted to an individual or a firm under any of the following categories provided the 'individual or the ~rm fulfills the qualification requirement as outlined against such category and after an application for memJ::>ershipis scrutinised by the Scrutiny Conmittee and approved by the Executive Committee of the Institute. CLASSIFICATION OF MEMBERS I. Associate Member

2. Fellow Member

INTERIOR DESIGNS PRINCIPLLES

15

3. 5. 7. 9.

AND PRACTICE

4.. Ufe Member 6. Student Member 8. Affiliate Member 10. Education Member

1\'ade Member licentiate Member Honorary Member Press Member

11. Donor 1. AssocIate Member Membership under this categorywiIl be granted to individuals only, who meet the following qualifications: (a) Completion of a degree or Diploma course in Architecture with not less than one year of full time experience in the field of Interior Design. (b) Completion of a course. of Secondary. $choollevel plus. tWQyears training in Interior Design from a GovernIJ1ent recognised Institute plus not less

than three yearsof full time experiencein the fieldof InteriorDesign. . (c) Persons practicing as Interior Designers for a minimum period of five years with proven abili(y and recognition in th~.field of Interior Design. Such abilities. shall be determined and approved by the appropriate officers of the institute appointed by Executive Committee. . Rights and prlYileges Associate Members shall have full voting privilege, shall be eligible. for office and for service on all committees. Associate Members . . shall have a right to

.

use the designation.
,

2. FeUowMember

,

.

. Membership under this category will be accorded to those who have 10 years of experience and standing in the field of Interior Design and who "ave consistently rendered 'distinguished services to the Institute and 1or who have made noteworthy contribution to the profession of ',Interior Design, Recommendations or nominations for' 'Fellow Membership' shall be made by: (a) Two or more office bearers of the institute. (b) Two or more fellow members. (c) Four or more members of the Executive Committee.

(d) Ten or more members of the institute. .' The nomination 1recommendations ,nust accompany a comprehensive statement giving details of qualifications, accomplish~nts,. and reasons for honouring any individual as a 'Fellow'. .

The nomination shall be scrutinised by the Scrutiny Committee and approved by the Executive Committee. Rights and PrivUeges Fellow Members shall have full voting privilege, shall be eligible for office and for service on all committees. Fellow Members shall have the right to use the designation. 'Fe"~w Members of the Indian Institute of Interior Designer' (F.I.I.D.) after their names. Entrance Fee: Rs. 500/Yearly Membersliip : Rs. 1000/-

-

.

3. Trade Member Membership under this category will be granted to: (a) Persons or rums executing Interior jobs or job work connected with Interior Decoration as CONTRACTORS. (b) Manufacturing or selling products or services required for interior Decoration and furnishing.

76

INDIAN INSTITUTE OF INTERIOR DESIGNERS

Membership

will be granted in the name in which the individual or the ftrm carries on business. The applicant shall nominate a person who shall .

represent the said firm. Rights and Privileges

Nominess of Trade. Members shall have full voting Privileges and shall be eligible for offtce other than that of PRESIDENT and for the service on all .

committees. Entrance Fee: Rs. 500/Yearly subscription: Rs. 2000/4. Life Membet

The AssociatelTrade Members who pay the requisite Life Membership Fee shall be called the Life member, in their respective category. Entrance Fee Subscription . Rs.IO,OOO/(a) Associate Life Members (new) Rs.' 5()()/(b) Trade Life Members Rs. 500/Rs. 20,000/S. Li~ntiat~

Members

The student or student members who have passed Interior Design 1 Ar~itecture recognisedDiploma I,Pegree course shall be eligible for enrolment as the Licentiate Member. The student membership of such member, if any shall cease on successful completion of studies and they. shall have to immediately apply to the institute for the registration changing member~hip category on prescribed form accompanied by certiftcates 1 documents. The .licentiate members shallihaveno vc;>tingrights and shall not be eligible for any offtce. The Licentiate member on completion of requisite time period and on acquisition of experience as vrescribed Associate Membership shall be eligible for registration under Associate membership on application.

{1:ntft~

.

r;i:~.f!X>b

;}'e,4tI;~'bi~..

7(X)/;

7. Honorary Member Honorary Membership will be offered to eminent and distinguished individuals of National 1International reputation holding a propUnCfntposition in Public life who may not be practicing as interior Designers or decorators, but who have rendered distinguished services to art and industry in general. Nomination/recommendation for Honary Membership may be made by anyone member of the executive committee. TI1eJllo~tic;>nl recommendation must accompany a comprehensive statement giving details of qualification, accomplishments and reasons for nominatjng. a person as a Honorary Member. The Nomination / recommendations shall be approved by the Executive ~ommittee after the same haS been recommended by the Scrutiny Committee.

1N'rnRIOR DESIGNS PRINCIPLLES

77

AND PRACfICE

Rights and Privileges Honorary Member shall have no voting privileges and shall not be eligible for office but may serve on committees. They may use the designation 'Honorary Member of the Indian Institute of the Interior Designers' (H.M.I.I.D.) after their names. Yearly Subscription: Nil

8. AfftllateMember Membership under this category will be accorded to individuals or organisations not necessarily engaged in the practice of Interior Design but whoilu:

nvolved in or associated with the Interior Design field such as:

.

\ \ (a) Executives or officers, fmns of Interior designers. Furniture Makers, Building Contractors, Manufacturers or sellers of materials used in Interior. Design and Decoration of furnishing jobs. (b) Executives employed by the Architectural 1 Civil 1 Interior Design fmns or Departments of private and 1or public organisation. (c) Individuab employed or atrtliated with a professional or Trade Member of the Institute in an executive of supervisory capacity. (d) Executives of Advertising 1 Public Relations Firms or Departments of industrial and commercial undertakings of any State or Central Government or Public Sector undertaking. (e) ArchiteCts not practiCing as interior designers. (f) LandScape Designers. (g) Industrial Designers. (h) Designers of decorative Arts and Crafts. (i) GraphicArtists . (j) Civil 1 Mechanical 1Electrical or Electronics engineers, planning or executing jobs of interior Decoration as consultants or as Project Managers, Executive engineers, Site Engineers for any Building project or employees of any Builders 1 Building 1 Contractor. (k) Interior Designers who fail to qualify under Associate Membership.

m~vidub:

:>rganlsations : Any Organisations or Fum interested in or associated with the Interior Design field such as advertising 1 public relations fmns or departments of Industrial and commercial undertakings, defence. establishments, fmns handling air conditioning. electrical sanitary and. plumbing work, civil work, builder, building eontract(}rS' fmns handling service for ~y interior decOrations or furnishing work for any type of building or building industry.

Rights and Privileges Affiliate Member shall have no voting privileges and shall not be eligible for office but may serve on. committees. F~: .

Individual

Membership

Entrance fee : Rs. 500/Yearly Membership: Rs. 700/Organisations Entrance fee : Rs. 500/Yearly Membership: Rs. 1500/9. Press Member Individuals who are actively engaged, in writing, editor or publishing of newspaper, Magazines or periodicats on the subject of Interior Designs and

7R

INDIAN INSTITUTE OF INTERIOR DESIGNERS

allied Arts. Membership may also be offered to newspapers, magazines and periodicals in the name of the publication. The applicant shall nominate a person who shall represent the said publication. "., Rights and Privileges Press Associate Members shall have no voting privilege and shall not be eligible for office but may serve on committees. Yearly Subscription: Nil 10. Education Member Persons who are principals of government recognise institutions imparting education in Architecture, directors of heads of the departments concerned museums and libraries.

Interior Design Fine Arts or Commercial Arts; and

Rights and privileges Education member shall have no voting privileges and shall not be eligible for office but may serve on committees. Yearly Subscription.: Nil

11. p.9nor Any individual or body incorporated, who donates to the institute an amount which is not less than the maximum Life Membership Subscription under any category, may be admitted as a Donor Member of the Institute subject to the approval of the application by the Governing body. No entrance fee will be payable by such a Donor who will be member for life. He will have no voting right and will not hold any office i(!:the Governing . ~~ i

Address:

Indian Institute of Interior Designer;; 2nd floor, Rachana Sausad . 278 Shanker Ghanekar marg Prabhadevi, MUMBAI - 400 025.

B. CODE OF CONDUCT

FOR ASSOCIATE

& FELLOW

MEMBERS

(Professional

Members)

1. Preamble (aj' The'initials A..I.I.D. or F.r.I.D.~fter .an Interior Designer's name means that an individual is a PROFESSIQNALMEMBER of lhe INDIAN INSTITUTE OF INTERIOR DESIGNERS either as an Associate or Fellow Member. Membership under this category is granted to an individual only, who is qualified by Education, and I or Experience as defined in the Institute Bye-laws to fulfill the role expected oLa PROFESSIONAL INTERIOR DESIGNER. (b) As such in becoming a Professional Member of the INDIAN INSTITUTE OF INTERIOR DESIGNERS, an individual agrees to uphold this CODE OF CONDUCT and the BYE-LAWS of the INSTITUTE and is thereby required to conduct his or her professional practice in a manner that will command the respect of their colleague~, clients, suppliers of goods and services, as well as the general public. 2. Respo~:~ibility to the public (a) Members shall advise compliance with all existing laws, regulations and codes governing business procedures and the practice of Interior Design as established by the Central or State Government or other jurisdiction in which they practice. (b) Members shall at all times consider the health, safety arid welfare of the public in spaces they design and shall make people aware whenever possible of risks I hazards if existing in built environment around them; (c) Members shall not seal or sign drawings, specifications, or other interior design documents except where the member or the member's firm has prepared, supervised or professionally reviewed and approved such documents.

79

INTERIOR DESIGNS PRINCIPLLES

AND PRACTICE

(d) Members shall not engage in any form of false or misleading advertising or promotional activities and shall not directly or indirectly provide misleading information about their professional practice. (e) Members shall not take any action intended to influence the judgment of a public official for the purposes of any project. (/) Members shall exercise discretion and dignity in their general professional conduct and in the use of their name and I.I.I.D. affiliation in self promotional activities. ~

3. Responsibility to the client (a) Member's Contractual agreement with a client shall clearly set forth the scope and nature of the project involved, the professional services to be performed, and the method of compensation for those services. (b) Members shall not undertake any professional responsibility unless they are, by training and experience, competent to adequately perform the work required. They shall discharge this responsibility with due integrity that will serve the best interest of their clients as well as the rights of those whose contracts they administer. (c) Members shall fully disclose to a client all compensation which the Member shall receive in connection with the project and shall not accept any form of-undisclosed compensation from any person / firm with whom the member deals in connection with the project. , (d) Members shall not divulge any confidential information about the client or the client's project, or utilize photographs or specifications of the project, , without the express permission of the client, with an exception for those specifications or drawiug~;Aver which the designer retains proprietary rights. (e) Members shall be candid and truthful in all their professional communications. ' (/) Members shall act with fiscal responsibility in the best interest of their clients and shall maintain sound professional relationship with suppliers, industry and trades to ensure the best service possible to the clients.

4. Responsibility to Other ProCessional Interior Designers .

(a) Members shall not interfere with the performance of another professional member's contractual or professional relationship with a client on the.job assigned. (b) Members shall not initiate or participate in any discussion or activity which might result in any unjust injury to another professional member's reputation or business relationships directly or indirectly. (c) Members shall not attempt, directly or indirectly, to supplant another member, by means of unfair inducements. Members shall not knowingly accept any professional assignment upon which another member has been acting without notifying the other member and upon being personally satisfied that the client has severed ~ntractual relationship with the said member. (d) Members may, when requested and it does not present a conflict of interest, render a second opinion to a client or serve as an expert witness in a judicial or arbitration proceeding, on obtaining consent in advance from the affected parties. (e) Members shall not endorse the application for Indian Institute of Interior Designers membership and / or certification of an individual known to be unqualified with respect to education, training, experience or character, nor shall. a member knowingly misrepresent the experienc~, professional expertise or moral character of that individual. (/) Members shall only take credit for work that actually been created by that Member or the Member's firm and under the Member's scope of work.

5. Responsibility to Suppliers of Goods & Services (a) Members shall offer Equal and Fair opportunity to suppliers of goods and services to profession. (b) Members shall act with fairness and integrity in the administration of the contracts between the clients and the suppliers of goods and services. They shall endeavour to see that suppliers get a fair compensation for their contributions and shall discharge their obligations in good and proper time in keeping with fair business practices. (c) Members shall acknowledge the contribution by their suppliers of goods and services by giving appropriate credits where due; in recognition of the team-work which is so essential for the successful completion of a given project.

INDIAN INSTITUTE OF INTERIOR DESIGNERS

80

6. Responsibility to the Profession (a) Members shall maintain standards of professional and personal conduct that will reflect in a responsible manner on the Institute and the profession. (b) Members shall seek to continually upgrade their professional knowledge and competency with respect to the Interior Design profession. (c) Members shall endeavour to contribute to the upgradation of the profession through dissemination of information add positive .and active support to the Indian Institute of .Interior Designers to enhance the status of the profession individually and collectively. Source: Indian Institute of Interior Designers, Mumbai.

I. LETTERING All the headings, explanatory notes and dimensions should be neatly written on the drawing. Ordinary writing is not good for presentation. A student c' interior design should devote enough time to practice lettering before starting the drawing. To do good lettering, the work must be done slowly. The present lettering style is known as single-stroke lettering. Other styles of lettering\can also be used but this is an easy and acceptable form of lettering. In single-stroke lettering a line of the required thickness is made with one stroke. The letters must be well formed with good relative width and uniform spacing. There is no standard relation between the height and the width of a particular letter. The actual width of the letter will depend on the space available for writing. Proper proportions of the various letters are estimated by eye. The rounded letters require most care and attention. Good jqdgement and practise are required to obtain proper spacing of the letters in a work. Writing method There are basically three types of letters normally used. They are: I. Block letters like A, B, C .. . . . . 2. Small letters like a, b, c . . . . . . 3. Numbers like I, 2, 3 . . . . . . Try to write all the letters with free-hand with pencil grade 'B'. Avoid using T-square and set-squares for writing letters. Choose proper spacing between the letters depending on the availability of space.

Steps

,

1. Block letters - Make rectangular boxes equally spaced with three horizontal lines as shown to any scale in the proportion of 1:1.5 (1 width and 1.5 length). Try to write all the letters within these boxes as shown. Take care in writing letters I, J & W proportionately because they may not fit exactly in the box. 2. Small/etters - Ma~ rectangular boxes equally spaced with four horizontal lines as shown to any scale in the proportion of 1: 1.5 (1 width and 1.5 length). Try 'to write all the letters within these boxes as shown. Take care in writing letters i, j, m & w proportionately because they may not fit exactly in the box. 3. NumIJers - Make rectangular boxes equally spaced with three horizootal lines to any scale in the proportion of 1:1.5 (1 width and 1.5 length). Try to write all the numbers within the boxes as shown.

LETIERING .

3

AND SCALES

2. SCALES (a) British Units

r:\

(b) Metric Units

Drawing Method . Steps ..

.,

l. Take.~ ordinary 30 eentimeter~ (em) scale. 2. Mark upto 20 em. ... J. For seale CDmark I 'em.as equivalent

=3

to 1 meter (m); 2 em

m; 3 em

= 3 m;

4 em

= 4 m;

5 em

= 5 m;

6 em

= 6 m; 7 em = 7 m;

8 em

= 8 m; 9

. em

=9 m; 10em =.10 m; 11em = 11m; 12em = 12 m; 13em = 13 m; 14em = 14m; 15 em = 15 m; 16 em = 16 xn;17 em = 17 m;18 em = 18 m; 19 em = 1911\l;20em= 20 m ~d so pn. Now, it is a seale of 1 em

4. For scal~ @ n1.ark2.em as equivalent to 1 meter (m); 4 em 1~ em = 9 m;20

= 1 m (or) 1:100.

= 2 m; 6 em = 3 m; 8 em =4

em = 10 m; and s() on. Now, it is a seale of 2 em

= =

= 1m

.

m; 10 em = 5 m; 12 em = 6 m; 14 em = 7 m; 16 em = 8 m;

(or) 1:50.

2 m; 15 em = 3 m; 20 em =4m and so on. Now it is a seale of 5 em = 1 m (or) 1:20. 6. For seale'@ mark 10 em as equivalent to 1 meter (m); 10 em 1 ni; 20 em = 2m and so on. Now, it is a seale of 10 em 1 m (or) 1:10. 7. For seale@ mark 20 em as equivalent to 1 pleter (m) and so on. Now, i.t is a seale of 20 em = 1 m (or) 1:5. 8. For seale @ mark 10 em as equi'(~eQ~to 3 meters; 5 em = 1.5 m; 4 em = 1.2 m; 3 em 0.90 m; 2 em 0.60 m; 1 em = 0.30 and based on this 5. For seale:;
=

.

higher digits should be worked out'. NQw, it is a seale of 10 em 3 meters (or) 1:30. 9. Simill!J'ly any type of $eale can. be made and u~ed for metrie units.

=

=

=

.

:- A. General assumptions

l. The followingobjectsare drawn: . L Square 2. Triangle 4. Hexagon 5. Circle

3. Rectangle 6. Octogan

2. Plan means appearance from the top of the object. 3. El€~vation means appearance from the side of the object. 4. Only one surface is seen at a time. B. Object dimensions I. 2. 3. 4.

The The The The

square object has six. surfaces. They are top, bottom and four sides. Length: 2.50 triangular object has five surfaces. They are bottom and four sides. Length: 2:60 rectangular pbject has'six surfaces. They are top, bottom and four sides. Length: hexagonal object has eight surfaces. They are top, bottom and six sides. Regular

m Width: 2.50 m. and Height: + 2.59 m. m. Width: 2.60 m and Height: + 2.60 m. 2.50 m Width: 5.00 m and Height: + 2.50 m. hexagon of 1.30 m. and height: + 2.50 m.

5. The circular object has three surfaces. They are top, bottom a.'ldside. Radius: 1.30 m and Height: + 2.50 m.

.

6. The. octagonal object has ten surfaces. They are top, bottom and eight sides. Regular octagon of 1.30 m. and height: + 3.00 m,

C. Drawing method Steps 1. Visualise each surface how it appears on that particular side. 2. Draw plan to scale 1:100 (or) 1 em 1 meter as shown, otherwise choose any convenient scale.

=

A. General assumptions 1. The structure ;s standing on the ground level and all elevation heights are given from 'the ground level as + 1.2 m.:!t means 1.2 m. above the ground level. Similarly + 3.7 m. means 3.7 m. from the ground level and -+4.9 m~\means 4.9 m. from the ground level. Normally all heights of any structure: should be indicated as (+) or (-) from the ground level, which is treated ~:f: O. 2. The structure is composed of the following shapes: (a) Rectangle of+ 1.2 m. height forms the b~e. * On the left side:

(b) Square of + 3.7 (c) Diamond shape (d) Square pyramid * On the right side: 3. Three different views are marked as L (left),

m. height over the rectangular base. of + 4.5 m. height over the squ~ base. of + 4.9- m. height over the rectangular base. F (front) and R (right):

B. Drawing method Steps 1. Draw to scale. 1:100 (or) 1 cm

= 1 meter

as shown, otherwise'choose

any convenient scale.

2. Draw the plan as per the measurements. , 3. Draw the 'F' side elevation directly below the plan so that orthographic projections ffom the plan can be t*en. Add the heights for the elevation. 4. Similarly draw 'L' and 'R' side elevations l'Qaintl,riniQga total height of + 4.9 m. f~m ground'1evel.

,

5. While drawing the elevations from three different sides, it should be observed that from each side elevation some parts of the structure are hi~den

and some are seen. Whenever an elevation is <Jr~wnthis should be kept in mind

!

Drawing Method Steps 1. Draw to scale I: 100 (or) 1 cm

= 1 meter

as shown, otherwise choose any convenient scale.

2. The structure is composed of the following shapes: (a) Rectangle of + 1.2 m. height forms the base. (b) Regular octagon of + 2.4 m. height over the rectangular base. (c) Square shaped' pyramid of + 5.00 m. height over the octagon On the right side: (d) Square of + 5.00 m height over the rectangular base. * 3. Draw the plan as per the measurements. 4. Draw the 'F' side elevation directly below the, plan so that orthographic projections from the plan can be taken. Add the heights for the elevation. 5. Similarly, draw 'L' and 'R' side elevations maintaining a total height of + 5.00 m from the ground level.

INTERIOR DESIGN

12

PRINCIPLES AND PRACTICE

(d) Table at Chair Table and chair are the most commonly used furniture in interiors, so drawing typical elevations of wooden table and chair will help in understanding other furniture.

Drawing Methf'~ Steps 1. Draw to scale I: 10 (or) 10 cm = I meter as shown, otherwise choose any convenient scale. 2. Draw the 'F' (front) side elevation directly below the plan, so that orthographic projections can be derived from the plan. 3. Only the front and the side elevations are drawn, because the back and other side elevations are the same as front and side elevations.

2. ORTHOGRAPHIC PROJECTIONS Orthographic projection is normally used to represent an object or structure, so that any line or angle can be measured directly and accurately. A line or surface is projected upon a plane by drawing perpendicular lines from points on the line or surface to the plane, and then joining them. The plan and three different sections of two structures and one room are worked out for conceiving the construction details with the help of orthographic projections.

A. General assumptions 1. The structure is 2. The structure is from the ground 3. The structure is

simple and easy to start learning of the orthographic projections. standing on the ground level (GL) and all heights shown in the brackets in the plan as + ] .0, + 1.5, + 2.0 and + 4.0 meters are given level; which is assumed as:t O. composed of the following shapes. (a) A base of + 1.5 m. height.

* On the left side: (b) A sunken square of + 1.0 m. height within the base. On the right side: (c) Two rectangles of + 2.0 m. and + 4.0 m. heights over the base. * 4. Three different cross sections are taken for orthographic projections. (a) Section-XY looks upwards. (b) Section-PQ looks towards the left side. (c) Section-AB looks towards the right side. Across section shows the imaginary cutting line and its viewing direction. This helps to understand the construction details of the structure. B. Drawing Method Steps 1. Draw to scale I: 100 (or) I cm

=I meter as shown, otherwise choose any convenient scale.

2. Draw the plan as per the measurements. Take the outer dimensions of lOx 5.50 m. to start the plan, so that it fits within the given dimensions. First, draw the base of the structure and then the innt::r parts. 3. Draw the cross section~XY below the plan. While cutting the structure along the XY line, the visible parts are' the base, the sunken 'square and the small rectangle.laJ(e-ihe orthogr
INTERIOR DESIGNS PRINCIPLES AND PRACTICE

16

(b) Structure

-2

A. General assumptions . 1. Structure - 2 is made of different shapes than square and rec\angles of the eariier exercis~. This exercise helps to understand the use of orthographic j

projections for shapes other than square and rectangle. 2. The structure is composed of the following shapes: (a) A base of + 1.0. height. (b) A square pyramid of + 3.0. height over the base. * On the left side: (c) An open cylinder of + 4.0 m. height over the base. * On the right side: 3. Three different cross sections are taken for orthographic projections: (a) Section - XY looks upwards. (b) Section - PQ looks towards the left side. (c} Section - AB looks towards the right side. A cross section shows the imaginary cutting line and its viewing direction. This helps to understand the construction details of the structure.

B. Drawing Method Steps 1. Draw to scale 1 : 100 (or) I cm = 1 meeter as shown, otherwise choose any convenient scale. 2. Draw the plan as per the measurements. Take the outer dime:nsions of 10 x 5 m. to start the plan so that it fits within the given dimensions. First draw the base of the structure and then the inner parts. 3. Draw the cross section-XY below the plan. While cutting the structure along the XY line, the visible parts are the base, the cut pyramid and the cut open cylinder. Take the orthographic projections shown in dotted lines from the plan and give the heights mentioned. The portions of the ~ructure which are cut in the imaginary cross section line should be shown in hatched lines. 4. Similarly draw cross sections AB and PQ on the left and right sides by using orthographic projections. 5. Sections are particularly drawn for easy visualisation while drawing. The left side (Section AB) and right side (Section PQ) are mirror images, while the front side (Section XY) is a true image.

18

INTERIOR DESIGNS PRINCIPLES AND PRAcrlCE

(c) Room A. General assumptions I. This exercise of the room helps to understand the use of orthographic projections for drawing building cross sections. 2. The room is made of brick wall, a door, four windows, ordinary cement flooring, RCC roof slab and a brick parapet. Note the direction of the north point, which shows the direction of north side in relation to the room. North point should be marked in any building drawing. 3. Three different cross sections are taken for orthographic projections. (a) Section - XY towards north side. . (b) Section

- PQ towards

(c) Section

- AB towards east side.

west side.

A cross section shows the imaginary cutting line and its direction. This helps to understand the construction details of the building.

B. Drawing Method I. Draw to scale 1:50 (or) 2 cm

= I meter

.

as shown, otherwise choose any conyenienrscale.

2. Draw the plan as per the measurements. Take the outer dimensions of 4.50 x 3':s0 m. to start the plan, so that it fits within the given dimensions. First draw the external wall thickness of 25 em. then mark the door (DI) and windows (WI) in the centre of the walls. Similarly mark windows (W2) to the corners of the wall. 3. For dimensions refer door & window schedule. 4. Draw the cross section - XY below the plan. While cutting the room along the XY line, the visible parts are the walls, flooring, windows, roof slab and parapet. Take the orthographic projections shown in dotted lines from the plan and give the heights as shown. 5. Similarly draw cross sections AD and PQ on the left and right sides by dsing orthographic projections. 6. Sections are particularly drawn for easy visualisation while drawing. The left side (Section AB) and -right side (Section PQ) are mirror images, while . the frontside (Section XY) is a true image.

.

Interior design depends upon the relationship of the following lihree aspects: l. Activity , 2. Space 3. Equipment 1. Activity - Activity is the task that is going to be performed in the given space. Normally an interior designer is asked to design within a given space. The given space may be adequate or inadequate for the activity. If the space is inadequate, then the activity should be squeezed within the given space without affecting the efficiency of the activity. Our railway compartments, aeroplanes and ships are good examples of squeezing an activity within a given space. This is the challenge of an interior designer. 2. Space - The given space is always fixed. The area and dimensions cannot be changed except marginally. However narrow spaces can be made to look spacious by providing mirror walls. It is only an optical illusion and does not increase. the real space. When the space is inadequate and small,

minimum area should be provided for circulation or movement of the people.

.

3. Equipment - - To perform any activity within a given space, some furniture is required. For example, in a dining rom, a dining table and chairs are needed. Based on the available space and number of persons to be accommodated, the size and shape of the dining table should be decided. Similarly for a bed room, the bed and wardrobe should be properly planned. Thus for good interior design, there is a need to co-ordinate these three aspects effectively. The following space standards are useful for good interior design.

The above space standards are extremely useful for il}terior design. These standards are derived out of practical. experience and useful fot Indian conditions. However they are not rigid. Whenever there is any doubt about the provision of any space, it is useful to take the measurements of that particular activity as we perform in our daily lives. ExERCISE 1. Prepare an existing interior layout of your residence. 2.Plepare an existing interior layout of your classroom.

Before knowing brick bonds, there is a need to know various brick sizes used in brick bonding and their technical terms. Even though we may not use .

these technicalterms in practice,they are usefulfor technicalcommunication. Drawing Method Steps .

1.)fraw to scale 1:10 (or) 10 cm

= i meter

as shown, otherwise choose any convenient scale. .

2. Assumptions made in the drawing: (a) Brick size 250 x 125 x 75 mm (or) 10" x 5" x 3" (b) l\llthe sizes of bricks are shown as parts of a full size brick like 1/4, 1/2 and 3/4 of the whole brick. This makes the understanding easy than

showingactualmeasurements.It is also the normalpractiseof cuttingthe brickson the site.

..

3. Normal brick sizes available in India are

(a) 250 x 125x 75 mm (or) 10" x 5" x 3" 1" (b) 225 x 113x 75 mm (or) 9" x 42" x 3" 4. The brick has six faces, which are known as top, bottom.J!eader

bricks. However ii is not seen in counuy bricks.

and stretcher faces. The top face has 'frog' in the case of pressed or machine-cut .

.

5. The various brick sizes shown are used for brick bonding depending on the need because without cutting the brick, brick bonding is not poSsible. 6. For all the brick si7es. full size bricks should be drawn. The differaat.sizes should be cut from the full size bricks.

Drawing method Steps 1. Draw to scale 1:10 (or) 10 cm 1 meter as shown, otherwise choose any convenient scale. 2. Assumed .brick size is Lx B x H =250 x 125 x 75 mm (or) 10" x 5" x 3" 3. The drawing is divided into two parts. The ~ttom part shows the isometric view of 1, 2, 3 & 4 brick courses and their overlapping with queen closers (half) to break the continuity and increase bonding capacity. 4. The upper part shows the elevation view from')l side. 5. English bond is compact and strong for walls having thickness of more than one a~d half bricks. It does not require strict supervision and skill for execution. When compared to Double Flemish bond, it is more costly and less pleasing in appearance.

=

Drawing Method Steps 1. Draw to scale 1:10 (or) 10 cm

= 1 meter as shown, otherwise choose any convenient scale.

2. Assumedbrick size is Lx B x H= 250 x 125x 75 mm (or) 10" x 5" x 3".

,

3. The drawing is divided into two parts. The bottom part shows the isometric view of 1, 2, 3 & 4 brick courses and their overlapping with qUfen closers (half) to break the continuity. The bricks are placed in a different way than English bond to increase the strength of bonding. 4. The upper part shows the elevation view from')l side. 5. Double Flemish bond is less compact and stronger than English bond but requires good workmanship and careful supervision. When compared to English bond it is cheaper in cost because more brick bats are used for one and half and two bri~k walls. It has better face appearance.

Fig. Eel. DilIerentBrieks

sizes (Scale 1:10 or 10 em

= 1 Meter)

Brick bonding is the interlacement of brick courses with mortar. It should have minimum vertical joints in any part of the brickwork because it is a weak part of the brickwork with uneven distribution of load. There are many types of brick bonds like Stretcher, Header, English, Flemish etc., Most frequently

used brick bonds are English and Double Flemish bonds. The use of these two bonds for one brick wall is shown in the. drawings. One brick walls are .

commonly used at present for exterior and interior construction of buildings.

INTERIOR DESIGN

30

PRINCIPLES AND PRAC1'ICE

3. TYPICAL WALL CROSS SECTIONS A. There are basically two ty~ of building constructiC'D (a) Load bearing wall construction - Most of the residential buildings and small structures are constructed with load bearing walls for economy and easy construction. (b) Non-load bearing wall or column construction.easy construction.

Major buildings and multi-storeyed constructions are made with columns for safety, economy and

B. Technical Terms (a) Foundation - It is the lowest prepared part below the ground level and transmits all the loads to the sub-soil to support the structure above the ground level. (b) Plinth level- It is above ~e ground level.and to the surface of the immediate floor level. (c) Plinth area - It is the built-up covered area at the plinth level. (d) Superstructure - The structure constructed above the plinth level. (e) Storey - The portfon of a building between any two floors. if) Sill level - The lower part below the window and the floor. (g) PCC footing

- Plain Cement Concrete (PCC) in the proportion

of 1:5: 10 or in any other desired proportion

is used as foundation

footing to the load

bearing wall construction. The base width of PCC should be twice the width of wall. (h) Brickfooting - Brick footing is stepped over a concrete bed. The number of brick steppings depends on the proposed width and loading of the wall. (i) Column footing - These footings are used to support individual columns. They can be stepped or have projections, as shown, in the concrete base. . These footings are in reinforced cement concrete to the required structural design. (j) RCC - In reinforced cement concrete (RCC) the concrete and reinforcing metal (normally steel is used) act together as one material. Concrete has good compressive strength and steel has got good tensile strength. In RCC, both these qualities of the materials are combined together to produce a

strong and economical material for construction.

.

(k) RCC plinth beam - RCC plinth beam is usw. to tie the columns at the ground level or plinth level. The wall can be constructed on this beam. (I) DPC - Damp proof course (DPC) is a layer of water repellent material like bitumen, plastic, metal etc. It is used wherever water entry is anticipated. This is normally used at the plinth level and over the roof level. (m) Flooring - The flooring is normally done with cement, stone or tiles. The thickness of the floor depends on the material used. (n) Skirting - Skirting is made with the same material used for the flooring. Skirting is made to protect the wall finish while washing the floor. (0) Door - A door can be defined as a movable barrier fixed to a wall opening for providing an access to the building or internal rooms. The door is fixed to the wall with door frame, and a movable shutter is used for closing and opening. Doors are made of different materials like wood, plywood, glass, metal etc., (P) Lintel- It is a horizontal supporting member used to span the openings of doors, windows, ventilators corridors etc., The use of a lintel is exactly the same of an arch but it is preferred because of easy construction and stability for small spans. They are made of wood, stone, brick and RCC. RCC

lintel is most widely used.

.

(q) Window - A window can be defined as an opening in the wall of a building to bring natural light, air, vision with protection from sun, rain and other extremities of weather. They are normally fixed to the wall with movable shutters for opening and closing. Windows are made Qf different materials . like wood, glass, steel, aluminium etc., (r) Sunshade - It is a sloping overhang provided over openings like doors and windows to provide protection from sun and rain beating. (s) Throating - It is a channel or groove under the sunshade to prevent rain water from ruooing inside the walls.

31

EXTERNAL PARTS

(t) Ferro-cement - It is made of cement and steel mesh. It is thin, light weight and easy to construct than brick wall. It can be made totbe required architectural design. (u) Parapet - It is that part of the wall constructed above the top roof slab. (v) Coping - Top of every wall not protected from the rain should be built to prevent the penetration of rain water with a slope. Known as coping.

C. Drawing method Steps I. Draw to scale: 1:5 or 20 cm

= I meter

as shown, otherwise choose any convenient scale.

2. Draw the ground level line and divide the drawing into two equal parts for load and non-load bearing walls. 3. Visualise the vertical cross section ofa wall with door and window. 4. Draw the total height (755 cms) of both the buildings. 5. Divide the buildings into plinth (45 cms), ground floor «310 cms), first floor (310 cms) and terrace (90 cms) levels. Thus the building levels become very clear for further internal detailing. 6. Draw the door (200 cms) and window (120 ctns) levels, excluding the floor thickness, for both the walls with lintels and sunshades. 7. For non-load bearing wall, draw the balcony projection (90 cms) with ferro-cement walls cf 8 ems thickness. 8. Draw the internal parts of both the buildings and notice the different parts.. The load bearing wall does not have column footing, RCC beam, balcony and ferro-cement wall of the column structure. Half-brick wall can also be used in column structure because the load is taken by the columns and beams. 9. Finally draw the foundation below the ground level as per the measurements and notice the difference in footings.

EXTBRNAL PARTS

33

4. ARCH AND LINTEL There is a need to understand the difference between an arch and lintel.

A. Ardl Arch is a structure consisting number of small wedge shaped units joined together with mortar. This is constructed to bridge across the openings meant for doors, windows, ventilators, cupboards etc., and to support ~e weight of the superimposed masonry in building construction. The wedge shaped units such as brick or other masonry blocks are arranged along a curved line to balance the load and exert a vertical pressure to be sustained by the supports below. The arches made of RCC and steel- are built of single unit. ,

B. Lintel It is a horizontal structural member used to span the openings for doors, windows, corridors and recesses to support the weight of the structure above if. The function of a lintel is exactly the same as an arch but it is preferred to arch because of easy construction. Though lintels are made of various materials such as wood, stone, brick, RCCand steel, RCC lintels are widely used these days.

C. Technical terms in arch work 1. Crown - Highest point of an arch. 2. Voussoirs - Wedge shaped or tapered-units forming the COUNeof an arch. 3. Soffit - Under surface of ail arch. 4. Intrados - Inner curve of an, arch. 5. Impost - The projecting course at the upper part of an abutment to stress the springing line. 6. Centre - Geometrical- centre point of an arch. 7. Rise - Vertical distance between the springing line and the highest point of an arch.

8. Bed joints - Joints between voussoirs;

,

9. Frontface - Front face of an arch. 10. Extrados - External curve of an arch. 11. Haunch- Lower portion of an arch. 12. Springers - Lowest voussoirs of an arch. 13. Spring;ng line - Imaginary horizontal line between two springers. 14. Span - Clear horizontal distance between the supports. 15; Abutment jamb. - Outer most supports Qfan arch. -

D. Construction of an arch Arches are constructed with radiating wedge-shaped blocks of stones or bricks called 'Voussoirs. The central one at the top is the 'crown' or 'key stone' and the horizontal ones at the sides are called 'Springers'. The 'springing line' is the point or level at which the arch springs from its support. This is often marked by a projecting form called the 'impost'. The solid walling or support on which the arch rests is the 'abutment'. The outer curve of the line of voussoirs is called the 'extrados' and the inner the 'intrados'. The under-surface is known as the 'soffit'. The 'span' oran arch is the distance between the supports or abutments and the 'rise' is measured from the springing line to the intrados. .

,

'E. Drawing method of arch Steps I. Draw to scale: 1 : 50 or 1 cm

= 1 meter

as shown, otherwise choose any convenient scale.

INTERIOR DESIGN

34

PRINCIPLES AND PRACTICE

2. The arch is assumed to be made of stone. /

3. The measurements of arch: (a) Span: 5.50 m. (b) Rise: 2.55m. (c) Impost projections from the wall on either side : 0.40 m. (d) The actual scale measurements may be taken for crown and voussoirs. 4. First take the span 5.50 m. and draw the imposts on either side. 5. Mark the centre of the arch and take the rise 2.55 m. to draw the intrados. 6. Take 3.55 m. radius from O1ecentre and draw the extrados. 7. Take 3.1 m. facIius from the centre and draw the middle curve between the voussoirsJ 8. Finally draw the crown and two rows of voussoirs as per the scale measurements. F.Construction

of a lintel

Lintels can be classified into various types like wooden, brick, stone, steel, RCC (Reinforced cement concrete) and Keinforced brick lintel. RCC lintels are extensively used in modem building construction in India, because they are economical, strong, durable, fire-proof and easy to construct. RCC lintels are constructed usually with a concrete mix proportion of 1:2:4 (1 cement, 2 sand and 4 stone aggregate) with reinforced steel bars. RC(: lintels may be either pre-cast or cast on the site. Pre-cast lintels are preferred for small spans upto 2.0 meters. Depending on the span and load, proper steel reinforcement should be provided.

G. Drawing method of lintel

=

1. Draw to scale 1:20 or 5 cm I meter as shown, otherwise choose any convenient scale. 2. All measurements are -given in centimeters. . 3. The brick size is assumed as 10" x 5" x 3" or 25 x 12.5 x 7.5 cm. . 4. Draw the span of 200 cm. and draw the RCC lintel 230 x 15 cm. over it. The overlap of 15 cm. on either side gives the necessary support to the lintel to carry the load., 5. Finally draw the exposed brick wall as per the given measurements.

36

INTERIOR DESIGN

PRINCIPLES AND PRACfICE

s. TYPES OF ARCHES There are various types of arches used in interiors. Some of the commonly used arches are: 1. Equilateral 2.Lancet 3. Triangular 4. Obtuse 5. Semi-circular 6. Segmental 7. Basket 8. Stilted 9. Horseshoe 10.Four-centred II. Shouldered Drawing method

=

1 meter as shown, otherwise choose any convenient scale. * Draw to scale 1:50 (or) 2 cm . 1. Equilateral arch - Draw a straight line with two centres of 'A, B' 200 em. apart. Take' ftl as centre and draw an arch of 200 em. radius. Similarly take 'B' as centre and draw an arch of 200 em. radius. Both these cut.at '0' forming an 'Equilateral arch' for the span 'AB' of 200 em. 2. Lancet arch - Draw a straight line with two centres of 'ftl, 'B' 400 em. apart. Take 'A' as centre and draw an arch of 300 em. radius. Similarly take 'B' as centre and draw an arch of 300 em. radius. Both these cut at '0, X, Y' forming a 'Lancet arch' for the span 'XV' of 200 em. 3. Triangular arch - Draw a straight line 'AB' of 200 em. Take an angle ()f 60° at point 'A' and draw a straight line 'AO' of 200 em. Similarly take an angle of 60° at point 'B' and draw 200 em. straight line 'BO'. Thus a 'Triangular arch' is formed over the span' AB' of 200 em. . 4. Obtuse arch - Draw a straight line with two centres of 'ftl, 'B' 150 crn. apart. Take 'A' as centre and draw an arch of 200 em. Similarly take 'B' as . centre and draw an arch of 200 em. Both these cut at '0, X, Y' forming an 'Obtuse arch' over the span 'XV' of 250 em. 5. Semi-circular arch- Take a centre point 'ftl and draw an arch of 150 em. radius cutting at points 'X', 'V'; which are in line with point 'ftl.. Thus a .. . 'Semi-circular arch' is formed over the span 'XV' of 300 em. 6. Segmental arch - Take a centre point' ftl. Then draw a straight line at gOem. distance above point' ftl. Taking' ftl as the centre point, draw an arch of185 cm. cutting at 'x, Y'. Thus a 'Segmental arch' is formed over the span 'XV' of 325 em. 7. Basket arch - Draw a straight line with two centres of 'ftl, 'B' 200 em. apart. Take the centre point and draw a perpendicular line below. Take another centre point 'C' on this line at a distance of 80 em. from' AB' . Draw the first arch 'XP' of 50 cm. radius with' ftl as centre. The point 'P' is obtained by taking an angle of 45° from 'Xftl. Draw the second arch 'QY' of 50 cm. radius with 'B' as the centre. Finally, draw the third arch ~PQ' .of 185 em. radius with 'c' as the centre. Thus a 'Basket arch' is formed with three centres over the span 'XY' of 300 em. 8. Stilted arch - Take a centre point 'A' and draw an arch of 150 em. radius cutting at 'PQ'. Draw another parallel straight line 'XY' at a distance of 90 . em. below 'PQ'. Join 'PX' jIlld 'QY'. Thus a 'Stilted arch' is formed OYerthe span 'XV' of 300 em. 9. Horseshoe arch":' Take a centre point' ftl, and draw a straight line 'PAQ'. !>raw another parallel straight line below this at 50 em. distance. Taking 'ftl as centre, draw an arch of 155 cm. radius cutting at 'PQ' and 'XV'. Thus a 'Horseshoe arch' is fonned over the span 'XY' of 290 em. 10. Four~centred arch - Draw a straight line with two centres 'ftl,'B' 160 em. apart. Take the centre point of the straight line and draw a perpendicular line below. Then draw below another parallel straight line with two centres 'C', 'D' 200, cm. apart !It a distance of 180 em. below' AD'. Draw the first arch 'XP' of 50 cm. radius with 'ftl as the centre. Draw the second arch 'QY' of 50 cm. radius with 'B' as the centre. Draw th
formed over the span 'XY' of 260 cm.

.

.

11. Shouldered. arch - Draw a strai~ht line with two centres' ftl, 'B' 200 em. apart. Draw the firSt arch 'XP'. of 50 em. radius with 'A' as the ccm~. Then. draw the ~d arch 'QY' of ~Q cm. radius with 'B' as the centre. Draw perpendicular lines 'PM' of 20 em. and 'QN' of 20 em.,' and join 'MN'. Thus a 'Shouldered arch,' is. farmed oYer the span 'XV' of 300 ern.

.

.

1. WOODEN JOINTS A. Technical terms ., . ~ (a) Sawing -:Jt is the process of cutting the wood with saw. .

.

.

-It is the process of shaving the wood to give it a dressed look. .

(b) Planing

(c) Chamfering (d) Bevel

.

- It is the process of planing the edges or corners of a wooden piece to fonnnormaIly .'

45° angle.

- In the process .of chamfering, if the angle fonned is not 45° ,then it is called as, bevel. - It is the process of shaping the wood as various units for construction by hand9r machine.

(e) Moulding

if) Metring - It is the process of joining two wooden pieces at an angle.

..

(g) Scribing -If one end of the wooden piece is cut to suit the shape of ~other (h) Rebating

-

It is the process

of cutting to sufficient

depth a rectangular

portion

wooden piece, it is known as scribing. of a wooden 'piece to fit in apother

(I) 'Shooting

- It is the process

of dressing the edges of the wooden piece to make them even.

(}) Housing

-

of sinking the edge of one piece into another.

(k) Groove

It is the process

- It is a recess

wooden

piece.

fonned in a wooden pieCe. The. groove may have different shapes to fit another wooden piece.

(I) Bead - It is the semi-circular projection fonned at the ~ges of the wooden pieces. , (m) Grounds - it is the process of fixing roug~ wooden blocks into the waIl to act as finn base lining for pictures 9r other ornamental things. The d','"

surfaces of the grounds should be flushed with the surface of the wall. (n) Laminating - It is the process of covering the structural woodwork wi~ )lect>rative laminates.

INTERNAL PARTS

(4) WoodeDJoiDts

Drawing method Steps

-

-1

1. Draw of scale 1 : 5 (or) 20 em =1 meter as shown, otherwise'choose any convenient sf81~'

two faces by cutting for .hal!"of depth. joints are formed by connecting two wooden piece$at right algIes to flush o~?r boltS. These Jomts are used where no projections at the The two members are Jomed by lappingooe over the other and binding them oy straps.aPd

~ Rightanglejoints-

~

joints are required.Four types of joints are shown.

W~~~

",

W~~'

,

(e) MortIse & Tenon (d)End lap 'part and then the upper part to fit in. All the joints are drawn in isometric view and the dimensions are as shown. First draw the .",ttom

3. Mi!ered joints

- These joints

are formed by cutting the members at an angle and joinin~'

Mitered joins of different forms are used to hide the ~nd

gratn of the wood. Four types of joints are shown:

W~ (e>-~~ spline.

,

'

'OO~&~~

(G)Ring . . while . ~wmg.. cross JOlOts All the JOlOts are drawn 10 180° x 30° angles, and the dimensions are as shown. Observe the types of joints are, shown: 4. PaaelliDgjoints - These joints are formed by joining two wooden members as sh~wn . 'ftIreC' (b) Housed (a) Blocked "

'

. (el Shoulder All joints are drawn S. Corner jointsseveral types b~t then the dovetail

'

'

'

while drawing. in 180° 30° angles and the dimensions are as s~_own.Observe the "ointP parallel or. at ri~t angles to their grain~. There may. be The~e joints are formed by connecting the ends and edges of dte~ber' IN and the dimensions are as shown. First !draw the grpove one, Important type, Dovetail joint,' is drawn. It is'drawn in isometric v'Ie part to fit in. '

x

'

42

INTERIORDESIGN PRINCIPLESAND~cnca

2. DOORS (a) Doors -1 The doors used in buildings can be classified into different types depending upon the materials used and their method of construction & operation. 1. Two panelled door In this door, the panels are fixed within a frame. These panels may be flat or raised or made to some design. There may be different types of panelled doors. They may be one panel, two panel, three panel, four panel, five panel and six panel doors depending upon the utility and choice. These doors are commonly used in any type of building.

-

2. Glazed and Panelled door and commercial establishments.

- It is also a panelled

door but the top panel is glazed with glass for transparency. These type of doors are used in offices

3. Glazed door - These type of doors are used to allow more natural light and also for transparency. In a small space such transparent doors give a spacious appearance to the interior without disturbing the activity to be performed. These doors are used in residential and public buildings.

4. Framed, Battended, Ledged and Braced door

- In this door, the vertical boards are 'Battens',

the horizontal pieces are 'Ledges' and the diagonal

pieces are 'Braces'. There are three other types in this category. They are Battened & Ledged; Battened, !..edged & Framed and Battened, Ledged & Braced doors. The strength of these doors depends on their construction. These doors are economical and normally used in residential buildings. 5. Flush door - The development of block board and plywood Led to the making of 'Flush door'. It is extensively used at present in the interiors of all types of buildings. It consists of a framework covered on both sides with laminated board or thick plywood. Thus it is totally flush and jointless on both the surfaces. These flush doors are manufactured in standard sizes for immediate use. There are two types in this category, They are 'Solid core flush door' and 'Hollow core flush door'. In the 'Solid core flush door', wooden core strips are glued together and faced on both sides by plywoOd sheets aridfiamed with. wooden strips. In the 'Hollow core flush door' , only wooden framework is made with top, bottom and intermediate rails with plywood sheets fixed on both

sides and.framedwith woodenstrips.

.

-

.

6. Flush & Sliding door Sliding doors are normally used when there is no spacefor-door opening or for economical use of. a limited space. These . doors are operated by slidingthe doors on the sides by using runners at the top and guides at the bottom. 7. Swinging door Swinging doors may be acting on one side or both sides. They are normally USed in passages, kitchen pantries, office cabin$ etc., The

-

shutters are fixed with special double action spring hInges which keep shutter closed when not in use. It is betterto have glazed panel for these doors, so that one can see the other while pulling or pushing the door. 8. Revolving doors - Revolving doors provide entrance on one side and exit on the other side by. rotating on a vertical axis. A circular space is provided with four shutters. It is preferable to have glazed panels on all the four shutters for easy movement. These doors are provided to control the entry and exit of people into the buildings. Drawing method Steps 1. Draw to scale 1:20 (or) 5 em

= 1 meter

2. The door size. is Length x Width

as shown; otherwise

=200 x

100 ems.

3. Rest of the measurements are as shown. 4. Observe the construction of different doors while. drawing.

choose any convenient

scale.

.

44

IN1ERIOR DESIGN

(bi~,..

PRINCIPLES ANDP-RACTICE

2

Glazed & Panelled (Plan, Elevation & Section) Drawing Method Steps 1. Draw to scale 1:10 (or) 10 cm

= 1 meter

as shown, otherwise choose any convenient scale.

2. It is a glazed and raised panelled door. 3. The vertical cross-section is taken through the frame,'glass and raised panel. 4. The plan or horizontal cross-section is taken through the frame and raised panel. 5. The door is held by metal holdfasts fixed into the wall. Normally th~~~holdfasts are fixed at the top, bottom and intermediate levels on both sides of the door frame. These are firmly fixed into the brick wall during the Cnlistruction. . 6. It is a single shutter door operated with hinges fixed to the frame on one side. 7. Draw the plan first as per the dimensions. 8. Then the elevation as per the dimensions. 9. Finally, the cross-section as per the dimensions. 10. Observe the fittings while drawing.

-

INTERIOR DESIGN

36

PRINCIPLES AND PRACfICE

s. TYPES OF ARCHES There are various types of arches used in interiors. Some of the commonly used arches are: 1. Equilateral 2. Lancet 3. Triangular 4. Obtuse 5. Semi-circular 6. Segmental 7. Basket 8. Stilted 9. Horseshoe 10. Four-centred 11. Shouldered Drawing method * Draw to scale 1:50 (or) 2 em = 1 meter as shown, otherwise choose any convenient scale. 1. Equilateral arch - Draw a straight line with two centres of 'A, B' 200 em. apart. Take' ft: as centre and draw an arch of 200 em. radius. Similarly take 'B' as centre and draw an arch of 200 em. radius. Both these cut,at '0' forming an 'Eq\.lilateral arch' for the span 'AB' of 200 em. 2. Lancet arch - Draw a straight line with two centres of 'ft:, 'B' 400 em. apart. Take' A' as centre and draw an arch of 300 em. radius. Similarly take 'B' as centre and draw an arch of 300 em. radius. Both these cut at '0, X, Y' forming a 'Lancet arch' for the span 'XY' of 200 em. 3. Triangular arch - Draw a straight line 'AB' of 200 em. Take an angle of 60° at point 'ft: and draw a straight line 'AO' of 200 em. Similarly take an angle of 60° at point 'B' and draw 200 em. straight line 'BO'. Thus a 'Triangular arch' is formed over the span 'AB' of 200 em. , 4. Obtuse arch - Draw a straight line with two centres of 'ft:, 'B' 150 em. apart. Take 'A' as centre and draw an arch of 200 em. Similarly take 'B' as centre and draw an arch of 200 em. Both these cut at '0, X, Y' forming an 'Obtuse arch' over the span 'XY' of 250 em. , 5. Semi-circular arch - Take a centre point' ft: and draw an arch of 150 em. radius cutting at points 'X', 'Y'; which are in line with point' ft:. . Thus a ," 'Semi-circular arch' is formed over the span 'XY' of 300 em. 6. Segmental arch - Take a centre point' ft:. Then draw a straight line at 80 em. distance above point' A'. Taking' ft: as the centre point, draw an a,rch of 185 em. cutting at 'x, Y'. Thus a 'Segmental arch' is formed over the span 'XY' of 325 em. 7. Basket arch - Draw a straight line with two centres of 'A', 'B' 200 em. apart. Take the centre point and draw a perpendicular line below. Take another centre point 'c' on this line at a distance of 80 em. from 'AB'. Draw the first arch 'XP' of 50 em. radius with 'ft: as centre. The point 'P' is obtained by taking an angIe of 45° from 'Xft:. Draw the second arch 'QY' of 50 em. radius with 'B' as the centre. Finally, draw the third arch'PQ'

. of

185 em. radius with 'c' as the, centre. Thus a 'Basket

arch' is formed with three centres over the span 'XY' of 300 em.

8. Stilted arch - Take a centre point 'A' and draw an arch of 150 em. radius cutting at 'PQ'. Draw another parallel straight line 'XY' at a distance of 90

em. below 'PQ'. Join 'PX' jUld 'QY'. Thus a 'Stilted arch' is formed over the span 'XY' of 300 em.'

,

9. Horseshoe arch ~ Take a centre point' A', and draw a straight line 'PAQ'. Draw another parallel straight line below this at 50 em. distance. Taking 'ft: as centre, draw an arch of 155 em. radius cutting at 'PQ' and 'XY'. Thus a 'Horseshoe arch' is formed over the span 'XY' of 290 em. 10. Four-centred arch - Draw a straight line with two centres' ft: ,'B' 160 em. apart. Take the centre point of the straight line and draw a perpendicular line below. Then draw below another parallel straight line with two centres 'C', 'D' 200, em. apart !It a distance of 180 em. below 'AD'. Draw the first arch 'XP' of 50 em. radius with 'ft: as the centre. Draw the second arch 'QY' of 50 em. radius with 'B' as the centre. Draw ~third arc~ 'PO' of 300 em. radius with 'D' as the centre. Finally, draw the fourth arch 'QO' of 300 em. radius with, 'c' as the, centre. Thus a 'Four-centred arch' is ,

'

,

formed over the span 'XY' of 260 em. 11. Shouldered, arch - Draw a straight,lipe with two centres 'A', 'B' 200 em. apart. Draw the firSt arch 'XP', of 50 em. radius with 'ft: as the centre. Then, draw the ~nd arch 'QY' of oQem. radius with 'B' as the centre. Draw perpendicular lines 'PM' of 20 em. and 'QN' of 20 em.,'and join '

,

'

'MN'. Thus

a 'Shouldered

arch,' is. formM over the span 'XY' of 300 em.

INTERIOR DESIGN

46

PRINCIPLES AND PRACI1CB

3. WINDOWS Windows are provided in the wall for sunshine, light and air circulation. Maximum number of windows should be provided on the external walls. The size and shape of the windows depend upon the activity performed in the room. The sill level is usually about one meter above the floor level and the tops of the doors and windows are normally kept on the same level. Windows &renormally provided with sunshades for protection against sun and rain beating.. Windows can be classified into different types on the basis of operation and.materials used. They can be broadly classified into the following types: 1. Casement windows 2. Pivoted windows 3. Sliding windows 4. Louvered window!l 5. Metal windows 6. Bay windows 7. Dormer windows 8. Skylights . I. Casement windows - The .~onstruction of casement windows is similar to door construction. A casement window consists of a frame, stiles, horizontal rails and panels with bars.. Side hinged o~ping part of th~.~~indow consisting of glass panes is known as casement. 2. Pivoted windows - In these windows, the shutters are made to swing round the pivots. The windows may be pivoted horizontally or vertically. The frames of these windows have no rebates. These windows are easy to maintain and admit more light. No bars or grills are used in these tYpe of

windows. 3. Sliding windows -These

.

windows work like sliding doors~ They are made of shutters which move horizontally or vertically on small roller bearings. . .

The necessary cavities are provided in the frame or walls to receive the shutters when windows are opened. . -4. Louvered windows - These windows provide free passage of air and light even when closed. They also provide privacy, protection against sun-beating and glare without affecting ventilation. They gather dust easily needing periodic cleaning, so they are normally used for toilets, workshops etc., These windows consists of a series of louvers made of wood, glass or metal. They may be fixed c;>rmoving.type. For economical .. construction.the angle of inclination of louvers is usually kept at 45°. Venetian blinds also serve similar purpose when fixed to any casement window. Venetian blinds fixed to a window are capable of being lowered or raised. They are equipped with a mechanical tilting device. These type 'of windows give maximum control of light and privacy without affecting ventilation. 5. Metal windows - At present the windows made of metals like mild steel, bronze, aluminium, stainless steel etc., are very popular. Steel windows, being economical, are extensively used and manufactured in standard sizes. The metal frame may be fixed directly to the wall or it may be fixed to a wooden frame. The. glass panes or shutters are fixed into the frame for tIte desired movements. Standard 'Z' shaped mild s~l sections are cut,

trimmedand weldedtogetherto fom1a rangeof stilDdardsized windows.These windowsare designedfor easy glass replacement.

.

The use of aluminium windows for buildings is also increasing.in big cities. Aluminium windows can be given any shape to ~uit the requirement. . .

and they do not need any painting or maintenance but the initial cost is comparatively high.

.

6. Bay or Bow windows - These windows project outside the external walls to form a projection callciJ as a 'bay or bow'. These type of windows provide more area of opening for light and ventilation from different directions. These windows also give extra space to the room and improve the appearance of the building.. . 7. Dormer windows - These are the vertical windows built on sloping sides of a pitched roof. These windows are provided to admit Jight and air to the

rooms. These windows improve the appearance of the building also.

.

.

8. SkY-light - These type of windows are usually fixed on the sloping surface of a roof parallel to its inclination. They bring natural light into the room and works as ventilator also by bringing fresh air: They are provided with fixed glass panels. To achieve good lighting and economy, skylights can be provided by substituting tiles by glass tiles of the same pattern ex: Mangalore tiles. Fibre glass skylights are increasingly used at present because they

are light in weight,easy to maintain;mouldedto the desiredshape.andavailablein varietyof coloursand designs. .. Drawing method

Steps

. \ .

. .

.

-

.

.

.

A. Draw to scale 1:20 (or) 5 cm= 1 meter as shown, otherwise choose any co~venient scale.

.

INTERNAL PARI'S

47

B. 1. Casement window-; Width x Height = 100 x 120 em. The dotted lines indicate the opening of window s;1utters. The shutters are fixed to a frame of 8 x 8 em. The window shutters are fixed .with glass within a frame of 5 x 5 em. 2. Pivoted window - Width x Height = 60 x 120 em. The dotted l~nes indicate the rotation of the window on the central axis fixed to the/top and'bottom

of the shutter. It is fixed to a frame of 8 x 8 em. The shutter is'fixed with glass within a frame of 5x 5 em. 3. Sliding window - Width x Height = 120 x 120 em. The gl~C?~ shutters slide one over the other on both ~id~s. The shutters are fixed to a frame of 8 x. 8 em. with sliding grooves provided at the top and bottom of both the shutters. Glass is fixed within the shutter frames of 5 x 5 em. ' 4. Louvered window - Widthx Height = 60 x 120 em. Glass louvers are fixed to a frame of 8 x 8 em. Numbe'r of louvers are equally divided within the . vertical span of 104 em. . . '

..

5. Metal windows - This is one type of metal window. There are several other types of/metal windows made to standard sizes or to the required size. In this case, Width x Height,= 100 x 120 em. The metal frame is 5 x 5 em. The inner shutters are 3 x 3em. The frame and shutters are made of 'L'

angle to fix one into the other; Glass is fixed to the shutters with putty. The dotted lines indicate the opening side of the shutters.

=

.

6. Bay or Bow window -Width x Height 150 x 120 em. The shape of the window is shown as the shadow below. It has three windows. One on both the corners and one in the center. The corner windows are single shutter windows and the centre window is double shutter window. The drawing shows the window in elevation. Draw as per the dimensions. 7. Dormer window ~ The dormer window is fixed to a sloping roof. The shape of the window is shown as the shadow on the side. Width x Height 50 x 65 em. with triangular frame at the top. Tbe-windowprojeets out of the sloping roof. Measure the drawing for any clarification.

=

8. Skylight':"

The triangular

glass skylight

width x height

= 60

x 55 em. is fixed to the sloping roof to bring light alone into the room below It is slightly

elevated above the roof slab level for the rain-water to conie down. Measure the drawing for any clarification.

INTERNAL PARTS

49

4. WOODEN PANELLING A. Wood is traditionally used for internal wall panelling. It has good acoustic properties apart from elegant appearance. Wooden panelling is fixed to vertical and horizontal ground pieces fixed to the wall. These ground pieces are fixed to the wall by nailing or screwing into the wooden plugs set into the wall. There are many other metals used at present for internal wall panelling for different reasons. B. Assumptions 1. In this exercise, blockboard panelling is shown where framework is not visible. The framework made of wooden ground pieces is screwed into the wooden plugs set into the wall. Six blockboards are screwed to this framework with visible screws for decorative appearance. The texture on the panelling is assumed, and it can be different also if needed. 2. Vertical corner ground pieces are 5 x 5 em. and middle ground pieces are 10 x 5 em. 3. Horizontal top and bottom ground pieces are 5 x 5 em. and middle ground pieces are 10 x 5 em. 4. Six blockboards of 100 x 140 em. each with 2 em. thickness are used for panelling. 5. The bottom skirting is in stone. 6. The plan is cut horizontally and the cross-section is cut vertically in the elevation to 'show the details of fixing. C. Drawing method Steps 1. Draw to sc'ale 1:20 (or) 5 em

= 1 meter

as shown, otherwise choose any convenient scale.

2. First draw the front elevation, then the plan and the cross-section taking the nelp of orthographic projections.

=

3. Take the outer dimensions of width x height 300 x 300 em. and then draw the inner parts. 4. The dotted lines in tl)e elevation show the framework for panelling. ,'...

-lNTERNAL

51

PARTS

S. PARTITION

WALL

, A. Non-load bearing partitions are commonly used in the interiors. They may be broadly classified into:

I. Brick and blockwork partitions

'

2. Stud and panel partitions 3. Slab and panel partitions 4. Moveable

partitions,

,"

-

'

1. Brick & blockwork partitions Brick or blockwork partitions are built with no foundation because they do not carry any weight. Lintels used over the openings can be lighter in weight. 2. Stud & panel partitions In these partitions the plate of the partition may'be fixed directly to the concrete floor. Timber lintels may be provided for small openings. The timber studs need not be heavy because they do not carry any weight. Metal stud~ can also be used instead of timber. 3. Slab &. panel partitions Slab and panel partitions can be speedily erected even.for large units. In this system, there are two types of partitions: (a) Plaster board - Plaster board is used in laminated or timber form for partitions. Laminated plaster board partitions consist of three layers of

-

-

plaster board bonded with adhesive, which are fixed to timber battens screwed to the floor and celing. (b) Slab - Slab materials .like timber boards, chipboards, plywood, fibreboard and wood-wool are used for partitions. In this method. the slab '

material is fixed within a timber or metal frame with heads. Then they are fixed to the walls, floor 'and ceiling with timber or metal studs., 4~ Movable partitions Movable partitions are used where the walls of a room are frequently opened to form one large floor area. In this system, then:-

-

are three types of partitions. (a) Sliding - Sliding partitions consists of a series of panels which slide in tracks fixed to.1he floor and ceiling. The mechanics of the pmtition are similar to those of sliding doors. If necessary, the panels can be stacked against the side wWlsor cupboards built into the side walls. (b) Sliding & folding - Sliding and folding partitions operate in a similar manner to sliding aM folding doors. They ~ normally used for smaller spans. ,

'

",-

- Screens

are usually constructed' of a metal or timber frame. It is fixed with plywood or chipboard inside. The screen is support((d with legs for free standing and easy movement.

(c) Screens

: B. AsSumptions ,-"

1. This is a slab partition commonly used in interiors. " 2. This partition is dividing a room of 300 em. width and 300 em. height.3. It has two fixed panels and a glass door in the centre. 4. The slab material is a particle board of 5 cm. thickness. 5. Beads of 2.5 cm. thickness for fixing the particle board and 1.0 cm. thickness for fixing the glass are used; '

C. Drawing method Steps 1. Draw to scale 1:20 (or) 5 em

= 1 meter

as shown, otherwise choose any convenient scale.

2. First draw the--front elevation, ~en the plan and the cross-section taking the help of orthographic projections. ;

3. Take the outer dimensions Qf width x height

=300 x 200 em, and draw the inner

parts.

'

6. SUSPENDED CEIL~G A. Suspend1d or false ceilings consists of framework suspended from the roof by metal or wooden hangers. /A ceiling finish' is fixed or applied to the undersiqe , of the framework. Suspended ceilings may be categorised into \

,

1. 10intless ' 2. Frame & Panel 3. Strip 4. Open Jointless'ceilings are made of in-situ construction. Framed and open systems are pre-fabricated in a factory andas$embled on the site. Jointless ceilings appear similar to direct ceilings, whereas framed and open ceilings expose the framework or the joints between the panels or strips. If the ceiling is used to .

conceal services, it is essential to provide proper access for inspection and maintenance of cables, pipes, ducts etC.; 1. JointlesS ceili~gs Jointless ceilings consists of a wooden or metal framework suspended by metal supports 01 hangers fixed to the roof. The ceiling finish may be made of large sheets of plaster-board or plaster applied.to metal lathing or sprayed materials. .

-

-

2.~rame & Panel ceilings The framework of a frame and panel ceiling is similar to jointless ceiling consisting of a grid of steel or aluminium members suspended from the roof by metal hangers. The underside of the ceiling is formed by small self-finished units. The fran1ework of a frame and panel ceiling may be either exposed or concealed. ' 3. Strip ceilings - Frame and strip ceilings are similar in construction to frame .and panel ceilings. Inverted aluminium or steel sections are suspended from the roof by steel wire hangers. Panels in the form of fiat aluminium or steel channel-sections is fi~d with profiled strips finished in a factory.

4. Open ceilings - Open ceilings consists of series of verticallyhanging strips or grids, which provide the illusionof a surface.This illusioncan be enhanced with more depth and close spacing of the sections. The grid is hung from the roof by metal hangers. The underside of the ceiling is not covered. B. Assumptions 1. This belongs to the category of frame & panel ceiling. However the framework is conCealed. ,

2. The size of the room is 400 x 200 cm. 3. The height of the room is 360 cm. The depth of the suspended ceiling from belpw the slab is 30 cm. This depth can be increased, if necessary, to accommodate service lines like cables, pipes, AC ducts etc depending upon the'Clear height available after putting the suspended ceiling. 4. The panels are made of plaster of paris (POP) boards. EaCh panel size is 50 x 50 cm. The panels are joined together forming a design. 5. Method of construction -:-Inverted 'L' shaped metal hangers are suspended from the slab at the joints ef the panels. The widthwise (i.e. 200 cm) wooden reapers are fixed to these metal hangers by screws. The lengthwise (i.e. 400 cm) wooden reapers are fixed to these widthwise reapers by screws or nails. The corner wooden reapers are directly fixed to the wall by screws or nails. Then the precast POP boards in panels are screwed to this framework creating a ceiling design. The design is left to the discretion of the interior designer. The suspended ceilings in cinema theatres, auditoriums and workshops are suspended from the steel rafters because normally they do not have RCC slabs due to large spans.

c. Drawing'method Steps 1. 2. 3. 4. 5. 6. 7. 8. 9.

Draw to scale 1:20 (or) 5 em 1 meter as shown, otherwise choose any convenient scale. First draw the elevation, then the cross-section. For elevation, draw the room size 400 x 200 cm. Draw the framework shown in dotted lines. Then draw the POP panel sizes of 50 x 50 cm. in broad dotted lines. This elevation is as it appears from below the ceiling. For cross-section, take the orthographic projections from the elevation. It is a vertical cross-section. Take the total depth of 30 cm. from below the RCC slab; which is supported by brick walls. Then draw the metal hangers, vertical & horizontal reapers and POP panels fixed to the framework. Metal hangers are -3 mm thickness, vertical wooden reapers (widthwise) are 3. x 3 em and horizontal wooden reapers (len~wise) are 5 x 2 cm size and POP panels are 1 em. thickness. ==

5S'

INTERNAL PARTS

7. MODULAR

FURNITURE

. .

Modular refers to a rational grid system of furniture. In this kind \of furniture system, vertical and horizontal members can be linked horizontally or

vertically to any desired configuration. Frames are made in rectangular grids for different .standard widths and heights. All connections are made with screws with a standard head. Fascia tiles made of particle board or MDF are fitted with patented connectors. These fit into' corresponding grooves in the frame. All .

tiles are gasketed to their frames to minimise sound and dust transmission. Tiles can be removed with a flat bladed tool. Glass can also be fixed into these

frames instead of fascia tiles. wherever needed. Electric wires can be entered from comer posts or sides of frames. Wires from ceiling are taken through a . power pole: Electrical delivery ducts are pierced for fitting switches above the worktops. Partitions are hollow and allow free horizontal movement of wires,. . This kind of furniture reduces recurring expense~ in the long run and gives flexibility in planning. Frequent changes can be made with minimUm cost. Installation time is also less. This kind of modular furniture is widely used in office and commercial establishments.

A. Assumptions

.

'The modular sections vary depending upon the manufacturing company. This particular unit is made for using a computer and working space. This metal .

modular furniture is made of the following. 1. Hollow corner sections of 5 x 5 cm. 2. 3. 4. S.

x

Hollow square tubes of 60 5 cm. and 90 x 5 cm. with provision for fixing fascia tiles an~ electrical wiring. SeparatJ drawers & shelves unit of75 cm. height, which can be fixed to the hollow sections>, Separate worktops of 1 em. thickness, which can be fixed to the hollow sections. The entire unit is fixed with standard screws and metal angles.

B. Drawing method Steps 1. Draw to scale: 1:20 (or) 5 cm

= 1 meter

as shown, otherwise choose any convenient scale.

2. The drawing is in isometric view... . 3. First, draw the modular frame as shown in isometric view. The inner lines are shown for proper understanding of the frame. The comers are of' . standard

size.

"

.

.

.

.

4."Then, draw the assembled unit with fascia tiles, worktop and shelves. The height of the wQrktopis 75 cm. The width of the drawers & shelves . is 50 em. Note: For drawing the "Isometric View" , please refer to the 'Isometric drawing' section.

A. The 'Ergonomic Triangle' Research has shown that the three most commonly used centres of activity in the kitchen are:

'

(a) Food storage area like fridge anq cupboards (b) Sink for washing and cleaning (c) Stove for cooking .

.

. The three centres of activity are joined together to form the 'Ergonomic triangle'.

To improve kitchen efficiency and reduce walking between these three centres, the total length of the distances between them should not excetd 6 meters. The ergonomic triangle should also be treated as a safety zone and walk ways through the kitchen should not pass through it because the cook carrying hot dishes from the stove to the sink does not come across people on their way out. However. this triangle is only imaginary', In the single line kitchen. these three centres of activity should be in straight line. In such a case, it should be remembered that right-handed people should always ha\1e the cooking side to the right of the sink beCause the arrangement should be from left to right.

B. Ideal kitchen plans . The way to tackle the layout of the kitchen depends on the size and shape of the available space. Basically the following shapes are commonly seen: (a) (b) (c) (d)

L-shaped Single line. Parallel -V-shaped

.

Drawing method Steps 1. Draw to scale I :50 for plans and I :20 for cross section as shown, otherwise choose any convenient scale. 2. Draw all the plans as, per the dimensions. 3. While drawing the plans, observe the ergonomic triangle for all shapes except the single line type. . 4. Location of the window should be near the stove and sink. Where it is not possible to have it for both, it is preferable to have it above the stove. It can be located near the sink if fume extractor is used above the stove. 5. The door and window widths may be taken as per the scale. 6. Normally the window height is 90 em. below the top of the door level. 7. Exhaust fan can be used to eliminate smoke and fumes.

58

INTERIOR DESIGN

c. Guidelines for efficient kitchen planning (a) Provide sufficient work top space. (b) Try to locate sink under a window for natural light and view. (c) The sink should have work surface or drain bo~d to keep vegetables and utensils. (d) Plac~ tall units at the end of base units, rather than in the middle for maximum uninterrupted working surface. (e) Use comer units to avoid wastage of space. (/) The work surface should be at least 30 em. on either side of the stove. (g) Do not locate a fridge ne;~t to a stove. (h) Do not fix wall cupboard above the stove unless they are above a fume extractor.

PRINCIPLES AND PRACTICE

A. The following types of staircases are commonly used in interiors I, Straight flight - There is no landing and an steps are made in one flight. 21 Quarter-turn stairs - The stepsare dividedinto two flightswith a quarterlanding. 3. Half-turn stairs - The steps are divided into two flights with a half landing in between like a dog-legged staircase. These are commonly seen in

public buildings. 4. 5. 6. 7.

'

Circular stairs - The steps are made in a circular form with an open well in the centre. Spiral stairs - The steps are made around a circular column. GeoT1U!tricalstairs - The steps are made in a semi- circular, form or in any other geometrical shape. Bifurcated ~tairs - The steps are divide4 into three flights with a central landing.

B. Requirements of

a good

staircase

.

]. The numberof steps in a flight shouldbe maximum12 and minimum3. . 2. 3. 4. 5. ,

Head room clearance height should not be less than 200 em. or 2.0 meters. Treads should be 25 em. to 30 em. wide excluding nosing. Riser should be 15 em. to 18 em. The maximum pitch 45° and the minimum pitch 25° is recommended.

C. Technical tenns used in staircases

.

(a) Tread - An upper horizontal part of a step on which foot is placed. (b) Riser - A vertical distance between two treads. (c) Going

(d) (e) if) (g)

-

The width of the tread excluding

nosing.

Laruling - A platform provided between two flights. Newel post - The vertical post placed at the top and the bott0l1!..~nds of flights supporting the handrails. Baluster - A vertical member supporting the handrail. The combined framework of handrail and baluster is known as balustrade. Soffit - The underside of stairs. '--' --,

61

STAIRCASES

- The outer projecting edge of a tread. This is nonnally rounded to give pleasing appearan~d Pitch or Slope The angle which the line of no~ing makes with the floor.

(h)' Nf!sing (I)

.

-

~

-

easy to climb.

(J) Handrail A protective bar placed at a convenient distance above the stairs for a handhold. (k) Angle post - A railing support at landings or other break of stairs. (I) Flight - A series of steps without any platfonn or landing or break in their direction. (m) .Step - This is a portion of a stair which comprised of the tread and riser. (n) Winders - Steps used 'for changing the direction of a stair. (0) Stringer - A sloping member which support the stairs; Normally seen in wOOdenstairs.

(P) Run - Total length of stairs in a horizontal plane including landing. (q) Head room - The minimum clear height from a tread to QverheadconslIUction in the terrace floor. 1. DOG~LEGGED STAIRCASE It is the most commonly used staircase with two flights and a landing. This drawing is basically to understand the technical tenns of various parts of the staircase. This is a RCC staircase.

A. Plan Steps 1. 2. 3. 4. S. 6.

Draw to scale 1:50 (or) 2 cm = 1 meter as shown, otherwise choose any convenient scale. All measurements are in centimeters. Length 320 cm and width 200 em. excluding wall'thickness of 25 COl.Tread is 25 COl. First draw a room 320 x 200 cm. with a wall thickness of 25 cm. Then draw the tread width of 25 cm. for all the 18 steps and leave the remaining space for landing at step 10. Mark the cross-section line 'XY'.

B. Vertical cross-section 'XV' Steps 1. Draw to seale I :20 or 5 cm

= 1 meter

as shown, otlterwise choose any convenient scale.

2. All measurements are ip centimeters. 3., The following assumptions are made:

*Tread 25.em.

e

* Riser 15 cm. * Handrail height 75qn. * Handrail thiclcnc;ss5 cm. * Baluster,thickness 3 cm.

4. 5. 6. 7.

* Newel posnhicknes,s 5 cm. * Wall thickness 25 cm. .. Floor height 300 em from Ground floor (GF) to Fast floor (FF) Draw the ~lope of 30° for the first and second flights with the landing -and wall. LeavingRCC slab thickness of 10 em. arrange the steps in two flights. Draw the handrail at 75 cm. height frQm the steps with balusters. ,Finally name the various ,parts.

STAIRCASES

63

2. SPIRAL STAIRS The treads and risers of spiral stairs turn around a central column. The tread should measure at least 30 mm. at the narrowest end. Spiral stairs are normally used when the space is inadequate for an ordinary staircase: It needs careful climbing and limited movement of people. Drawing Method Steps 1. Draw to scale I:20 or 5 em

=I meter as shown, otherwise choose any convenient scale.

A. Plan 2. First draw the inner column with a radius of 10 em. 3. Then draw the outer circle with a radius of 10 + 75 = 85 cms. and handrail thickness of 3 cm. 4. Divide the outer circle into 20 equal pans. This can be worked out based on the formula for calculating the circumference of a circle i.e.. 2 n r. After calculating the circumference of the outer circle, divide it into 20 equal pans for 20 steps. B. Front Elevation 5. Take the total floor height of 300 cms or 3 meters; 6. Take the onhographic projections from the plan to draw the front elevat!on. 7. The height of the handrail is 75 cm. or 0.75 meters. For the curved handrail take 75 cm. height from each step and then join all the points. 8. For the curved stairs. project the outer and inner points of each step and take the height of riser 15 cm. venically along the central column.

STAIRCASES

65

3. GEOMETRICAL STAIRS Geometrical stairs are normally semi-circular in shape for easy climbing and shorter climbing distance. The tread should measure atleast 30 mm. at (he narrowest end. Geometrical stairs are normally used for fancy when there is adequate space. The climbing is easier than spiral stairs and they are normally preferred in domestic buildings. Bigger size staircases are used in public buildings also. Dra~ing Method Steps 1. Draw to scale I :20 or 5 cm

= 1 meter

as sho\\TI. otherwise choose any conveniept scale.

A. Plan 2. First draw the inner semi-circle of 50 cm. radius with handrail thickness of 3 cm. . . 3. Then draw the outer semi-circle of 50 + 3 + 70

= 123 cm. radius

with handrail thickness of 3 cm.

4. Divide the outer circle into 20 equal parts based on the formula for calculating the circumference of a full circle i.e.. 2 n r. 5. The circumference of 123 em. radius full circle should be made into half for the semi-circle. then divide it into 20 equal parts for 20 steps. .

B. Front elevation 6. Take the total floor height 0(300 cm. or 3 meters. 7. Take the orthographic projections from the :plan to draw the front elevation. 8. The height of the handrail is 75 cm or 0.75. For the curved handrail take 75 cm. height for each step and then join all the points. 9. For the curved stairs. project the outer and inner points of each st(~par.d take the height of riser 15 cm vertically.

1. COLOUR WHEEL Light is linked with colour because light is the source of all colours. Colour is in sunlight also. When sunlight passes through a prism, it seperates into~ different colours. When light comes!into contact with a surface and reflects all the wavelengths equally, then we see white colour. If the surface absorbs all the wavelengths then we see black colour. Similarly, if the surface does not absorb the blue rays but absorbs all the other colours, then we see blue .colour. Thus the colour is the name given to the reflections of wavelengths from different surfaces. A. Colour wheel It gives good understanding of colours. It consists of the colours of the rainbow arranged in a circular fashion. This colour wheel can be used to explain the main relationships of colours. An understanding of these relationships is useful for choosing furnishings, coverings, paints and other colour materials. Drawing method Steps

=

1. Draw to scale I: 1 (or) 1 em I meter as shown, otherwise choose any convenient scale. 2. Draw the outer circle with 700 em. radius. 3. Draw the inner circle with 500 em. radius. 4. Divide the circle with 600 angles as shown. 5. First choose the primary colours: Red, Blue and Yellow, and paint them. 6. Then choose the secondary colours by mixing the primary colours. Primary

* *

*

Thus

colour (1)

+ + +

Primary colour (2) Yellow Yellow

=

Secondary colour Red = Orange Blue = Green Red + Blue = Violet the secondary colours obtained after mixing a pair of primary colours are orange, green and violet. Paint them within their respective areas.

68

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

7. These six colours: Red, Blue, Yellow, Orange, Green are Violet and called standard colours. 8. To get intermediate colours 'in the outer circle, mix the primary colour with its adjacent secondary colour. 9. Thus the intermediate colours obtained are Primary Colour Red

+ +

Red

+.

Blue Blue Yellow Yellow

+ + + +

Secondary Colour Orange Violet Violet Green Green Orange

= = = = = =

Intermediate colour 1.(R+O) 2 (R+V) 3 (B+V) 4 (B+G) 5 (Y+G) 6 (Y+O)

10. Care should be taken while mixing the colours. They should be mixed evenly to obtain good colours.

B. Colouring terms 1. Hue: Name of the colour. Ex : Red, blue etc., 2. Value: Amount of lightness or darkness in colours by mixing white or black colour. .

.

3. Intensity or Chroma. : It is the brightness or dullness of a colour. To reduce the intensity of a colour, add its complemeniary colour to make it soft. .

4. Tint

or Tone: It is the softness of colours nearer to white. 5. Harmonious colours: Colours adjacent to each other on the colour wheel. Ex : green & yellow ~tc., 6. Contrast or Complementary colours: Colours which are directly opposite to each other on the colour wheel. Ex: red & green. blue & orange eta' I

INTERIOR DESIGN

70

PRINCIPLES AND PRACTICE

2. CONTRAST COLOUR SCHEMES 1. Monochromatic ,

A monochromatic

'

colour scheme consists of using one colour in varying intensities.

D.-awing method

Steps

,

1.

2. 3. 4. 5. Ex:

=

Draw to scale 1:1 (or) 1 cm 1meter as shown, otherwise choose any conven~rnt scale. Draw the outer circle of 600 cm. radius and divide it into six inner circles as pet,the given measurements. Then divide the circles with 60° angles as shown. \ Thus the intensities of six different colours is worked out in this excercise. To work out the monochromatic colour scheme, choose anyone colour and add its ~omplementary colour in varying intensities. Choose orange colour and add its complementary colour blue. Add the complemenuJy \, colour in varying intensities 3$ shown below:

\

In the 1st

circle add

one drop of blue colour.

In In In In In

circle circle circle circle circle

two drops of blue colour. three drops of blue colour. four drops of blue colour. five drops of blue colour. six drops of blue colour.

the 2nd the 3rd the 4th the 5th the 6th

add add add add add

Thus the monochromaticcolour schemeof orangeis obtained.

\ \

6. Similarly it can be workCd out for other colours like Red, Violet, Blue, Green and Yellow\by adding their respective complementary colours in varying intensities as described above. \ ,

2. Complementary Complementary colours are directly opposite to each other on the colour wheel. Drawing Steps

method

1. Draw to scale 1:1 (or) 1 em

= 1 meter,

otherwise choose any convenient scale.

2. Draw the outer circle with 600 cm. radius. 3. Then draw two inner circles of 400 and 350 em. radiuses. 4. Split the colour wheel with 50 cm. gap between the colours for easy understan~ng. ,5. Thus the complementary colour schemes are: * Red & Green * Violet & Yellow * Blue & Orange * (0 + R)'& (B +G) * (R + V) & (G + Y) (B + V) & (Y + 0) *

7'2

3. CONTRAST COWUR 3. Double complementary Double complementary .

SCHEMES colours consists of a pair of complementary colours on the colour wheel.

Drawing method Steps 1. Draw to scale 1:1 (or) 1 cm

= 1 me~r

as shown, otherwise choose any convenient scale.

2. Draw. the colour wheel as sh~wn earlier, and split it with 50 cm. gap between the iolours as shown. 3. Thus the double complementary colour schemes are: G) * Red & (0 + R) and Green & (B + * Violet & (R + V) and Yellow & (G +Y) * Blue & (B + V) and Orange & (Y + 0).

4. Split complementary Split complementary

colours consists. of tWo colours that join its complements on. the coloutwheel.

Drawing method Steps ,

1.1

Draw to scale 1:1 (or) 1 cm

= 1 meter as shown, otherwise choose any convenient scale.

2. Draw an outer circle of 600 cm. radius; 3. Divide the circle ink> two parts as top and bottom. 4. Draw an inner semi-circle of 400 em. radius in the top part of the circle. 5. Split the circle into 12 sectors with 50 cm. gap in between, and JIlark as shown. 6. Mark all the primary & secondary colours in the bottom part of the circle, and mark their complementary coloursindte 7. Thus the split complementary. colour schemes are: * Red and (B + G) & (G + Y). Observe green is common. * Orange and (B + V) & (B + G). Observe blue is common. * Yellow and (R + V) & (B + V). Observe violet is common. * Green and (R + 0) & (R + \7). Observe red is common. * Blue and (Y + 0) & (R + 0). Observe orange is common. * Violet and (G + Y) & (Y + 0). Observe yellow is common.

top of the circle.

4. CONTRAST COLOUR SCHEMES

s. 1iiad Triad colour scheme combines three colours obtained by placing an equilateral triangle on the colour'wheel. By turning the equilateral triangle on the colour wheel different combinations can be obtained. Drawing method Steps 1. Draw to scale 1:1 (or) 1 cm

= I meter

as shown, otherwise choose any convenient scale.

2. Draw the colour wheel as shown earlier, and split it with 50 cm. gap in between the CQloursas shown. 3. Draw four equilateral triangles. in dotted lines. The sides of the bigger triangles is 900 cm. and smaller triangles is 300 cm. 4. Thus the triad colour schemes are * (0 + R), (V + B) & (G + Y) (V + R), (B + G) & (0 + Y) * * Red, blue and yellow * Violet, green and orang~

6. Tetrad Tetrad is formed by any four colours on the colour wheel, which are adjacent to one another. DJawing method Steps .. I. Draw to scale .1:I (or) I cm

= I meter

as .shown, otherwise choose any convenient scale.

2. Draw the outer circle with 600 cm. radius. 3. Then draw two inner circles of 400 and 350 em. radiuses. 4. Divide the circles with 60° angles as shown. 5. Thus two tetrad colour schemes are * Yellow, orange, red & violet. * (V + R), (V + B), (B + G) & (G + Y) 7. Guidelines for good colour schemes (a) In all colour schemes one colour should dominate. This basic colour should occupy 60 to 70 percent of the whole colour scheme. (b) Definite colour schemes like hanrtoniotls, complementary

or triad are recommended.

(c) A safe colour scheme consists of tints and shades of one colour. (d) A colour scheme should be definitely dark or light. (e) Either warm (red, yellow, orange) or cool (with bluish shade) colours should-dominate.

if) Every colour scheme must have a dominating colour and secondary colour. (g) A neutralised colour (grey) is best for large areas. (h) Rely on colours to brighten dark areas.

.

--

Rendering 1'echlliques (with pen." ink) A. Rendeti~gtecl)niques are basically used for presentation drawings. There may be many techniques in colour, but this exercise is meant to introduce

rendering t~hniques in pen and ink.

.

Drawing Method B. There areJhree types of rendering techniques shown in the drawing: 1. Straight lines with pen, set square and T-square. 2. Freehand lines with pen. 3: Broken straight lines with pen, set square and T-square. C. Any number of combinations can be tried with the three techniques. D. The drawing is divided into three parts: 1. The left part shows the rendering techniques. 2. The right part shows rendering techniques of some important building materials. The actual sizes of the building materials may be used for. the drawing. 3. The bottom part shows the elevatiun of a residence, where rendering technique & Q) or in combinations of ,<2>& Q) and Q) &
Drawing method

Steps 1. Draw to scale I: 10 (or) 10 em

= I meter

.

as shown, otherwise choose any convenient scale.

2. Al measurements are given in centimeters in the drawing. 3. Take the set square 30°, 60° & 90° and use only 30° angle on both sides as indicated because isometric views are drawn/with 30° angle only.

4. All right and left side measurements should be taken on 30° angular line (ex: OR and OL'lines as shown). All heights should be taken vertically on 90° angular line (ex: OH line as shown). Measurements drawing isometric views. ,

should not be taken on a horizontal line. It is very important to keep this in mind while

5, Divide the object into two sides as left and right sides. Take the measurements given in the drawing. .

6. All hidden 'lines are shown in dotted line for easy understanding. 7. Size of the Square is Lx B x H = 25 x 25 x 25 ems.

.

THREE DIMENSIONAL

79

VIEWS

8. Size of the Rectangle is L x B x H = 40 x 25 x 25 ems. 9. Size of the Triangle is L x B x H 25 x 25 x 40 ems. First draw a rectangle of 25x 25 x 40 ems. Then draw the triangle in it by taking a centre

=

point on the top 25 em. Hne and join it on both sides to the bottom 25 em. line.

'

10. Size of the regular Oetogan is 10 em. on all sides and height of 40 em. First draw a rectangle of 25 x 25 x 40 ems, Then draw regular octogan of 10

em. in it on the top and bottom planes, and then join them to get the height.

'

II. It is very useful to practise isometric views of different other objects.

(6) Structures Drawing Method Steps I. Draw to scale 1:100 (or) 1 em = I meter as shown, otherwise choose any convenient scale. 2. All meaSurements are given in meters in the drawing. 3. Take the set square' 30°, 60° & 90° and use only 30° angle on both sides as indicated in the drawing because IsometricViews are drawn with 30° , an~~~ '

'

4. Divide the structure into two sides as left and right sides. 5. Take the measurements given in the drawing. 6. Take measurements of length and width on the Left and Right sides, and fleight vertically.

7. All hidden Hnes are shown in dotted Hnes for easy understanding.

, '

8. Firstdraw the base of the structure and then construct the drawing over it. For structure-I, draw 5.00 x 5.00 meters square base aud then CiJnstrtuct the parts over it. Similarly, for structure-2, draw 5.00 x 5.00 meters square base with cut comers and then construct, the parts over it. This way j't is

easy and unambiguous.

,

9. Any doubts can be cleared by placing the set square on the drawing shown.

,

THREE DIMENSIONAL

VIEWS

79

=

8. Size of the Rectangle is L x B x H 40 x 25 x 25 ems. 9. Size of the Triangle is Lx B x H = 25 x 25 x 40 ems. First draw a rectangle of 25 x 25 x 40 ems. Then draw the triangle in it by taking a centre

point on the top 25 em. line and join it on both sides to the bottom 25 em. line.

.

.

10. Size of the regular Octogan is 10 em. on all sides and height of 40 em. First draw a rectangle of 25 x 25 x 40 ems. Then draw regular octogan of 10 .

em. in it on the top and bOttomplanes, and then join them to get the height. 11. It is very useful to practise isometric views of different other objects.

(b) Structures Drawing Method Steps'

'

L Draw to scale I: I00 (or) I em

= I meter

as shown, otherwise choose any convenient scale.

2. All measurements are given in meters in the drawing.,

. 3. Take the set square' 30°, 60° & 90° and use only 30° angle on both sides as indicated in the drawing . because Isometric. Views are drawn with 30° , angle only.'

4. Divide the structure into two sides as left and right sides. 5. Take the measurements given in the drawing. 6. Take measurements of length and width on the Left and Right sides, and Height vertically.

7. All hidden lines are shown in dotted lines for easy understanding.

.

8. First draw the base of the structure and then construct the drawing over it. For structure-I, draw 5.00 x 5.00 meters squ~re base arid then cunstr;uct the parts over it. Similarly, for structure-2, draw 5.00 x 5.00 meters square base with cut comers and then construct the parts over it. This way it is easy and unambiguous. 9. Any doubts can be cleared by placing the set square on the drawing shown.

INTERIOR DESIGN:

82

PRINCIPLES AND PRACI1CE

(c) Table and Chair .

Drawing method ,

Steps .

1.

Draw to scale 1:10 (or) 10 em

= 1 meter

as shown, otherwise choose any Convenient scale.

2. All measurements are given in centimeters.

.

3. Table and Chair are the most commonly used indoor furniture. The ability to draw them in an isometric view helps in the preliminary visualisation of .

furniture. 4. Take a comer point and take angular lines of 300 on both sides. .

5. For Table:

.

(a) Draw a box ofL x B x H

= 90 x 45 x 73 ems.

(b) Draw the top band of 15 em. and bottom band of 5 em. (c) Draw the legs, and remove the unwanted lines for the view of the table. . 6. For chair: (a) Draw a box of Lx B x H 45 x 45 x 43 ems, which forms the seating portion of the chair.

=

(b) Draw the top band of 5 em. and bottonrband of 5 em. (c) Draw the legs.

(d) Add the back rest of L x B x H = 45 x 5 x 45 ems. (e) Draw the net portion in the centre Lx B = 35 x 35 ems. for the seat aDd the back rest. Then remove the unwanted lines for the view of the chair. 7. It is very useful to practise isometric views of different tables and chai~~__-

84

INTERIOR DESIGN

(4) Bed Room

A. General assumptions 1. Length and width of the bed room (inner dimensions)

2. Height of the bed room from floor level 3. Depth of the wardrobe on the left side 4. Window size: (a) Beside the wardrobe B x H (b) Behind the bed B 'x H

x 300 ems (or) 4.0 x 3.0 meters.

=300 ems (or) 3.0 meters.

=60 ems.

= 120 x

=90 x

=400

120 ems (or) 1.2 x 1.2 meters.

120 ems (or) 0.90 x 1.2 meters.

5. Bed: (a) Size Lx B x H

= 200

x 200 x 20 ems (or) 2.0 x 2.0 x 0.20 meters.

(b) Support below the bed Lx B x H = 200 x 120 x 20 ems (or) 2.0 x 1.2 x 0.20 meters. 6. Side cupboards (a) Beside the bed on both sides Lx B x H

= 50 x 40 ><30 ems.

(b) Extreme comers on both sides Lx B x H

(or) 0.5 x 0.4 x 0.3 meters.

= 50 x 40 x 70 ems. (or) 0.5

x 0.4 x 0.7 meters.

(c) Supportbelow the cupboardsLx B x H = 100x 30 x 10ems. (or) 1.0 x 0.3 x 0.1 meters. 7. Size of floor tiles Lx B = 25 x 25 ems (or) 0.25 ~p.25 meters. 8. Actual measurements to the required scale should be used for the drawing. B. Drawing method

Steps 1. Draw to scale 1:40 (or) 10 em

.

= 4 meters

as shown, otherwise

choose any convenient

scale.

2. Fix the centre point and take 30° angle on either side. 3. Draw the outer dimensions and height of the bed room with window and wall thickness of 25 ems. 4. Then draw the bed with side cupboards with actual heights measured to a scale as given above. 5. Draw the wardrobe as per the measurements. 6. It is essential to visualise the room before drawing. 7. Isometric view is an effective and easy way of communicating interior design ideas.

PRINCIPLES ANi> PRACTICE

INlERIOR DESIGN. PRINCIPLES AND PRAcrICE

86

2. AXONOMETRIC vmw (a) Objects Drawing Method Steps 1. Draw to scale 1:10 (or) 10 ern

= I meter

as shown, otherwise choose any convenient scale.

2. All measurements are given in centimeters in the drawing. 3. Take the set square 45°, 45° & 90° and use only 45° angle on both sides as indicated because Axonometric views are normally drawn with 45° angle on both sides. The set square 30°, 60° & 90° can also be used but the view will be close to an isometric view because one angle is 30°. 4. All right and left side measurements should be taken on 45° angular line (ex: OR and OL lines as shown). All heights should be taken vertically on 90° angular line (ex: OH line as shown). Measurements should not be taken on a horizontal line. It is very important to keep this in mind while drawing Axonometric Views. 5. All the objects drawn in Isometric View are drawn again in Axonometric View with the same scale, so that comparision can be made. Such a comparision will help to decide which view is good for presentation. 6. Divide the object into two sides as left and right sides. Take the measurements given in the drawing. 7. All hidden lines are shown in dotted lines for easy understanding.

8. Size of the square is L x B x H

=25 x 25 x 25 ems.

~. Size of the Rectangle is Lx B x H = 40 x 25 x 25 ems. 10. Size of the Triangle is L x B x H = 25 x 25 x 40 ems. First draw a rectangle of 25 x 25 x 40 ems. Then draw the triangle in it by taking a centre

point on the top 25 em. line and join it on both sides to the bottom 25 em. line. 11. Size of the regular Octogan is 10 em. on all sides and height of 40 em. First draw a rectangle of 25x 25 x 40 ems. Then draw regular octogan of 10 em. in it on the top and bottom planes and join them to get the height. 12. It is very useful to practice Axonometric Views of different other objects.

Drawing Method Steps 1. Draw to scale 1:100 (or) 1 cm

= 1 meter

as shown, otherwise choose any conveniP:nt scale. .

2. All measurements are given in meters in the drawing. 3. Take the set square 45°, 45° & 90° and use only 45° angle. on both sides as indicated in the drawing. 4. All the structures drawn in isometric view are drawn again in axonometric view with the' same scale, so that comparison can be made. Such a

comparison will help to decide which view'i&~ood for presentation. 5. Divide the structure into two sides aS~ft

.

and Right sides.

6. Take the measurements of length and width on the left and right sid~s, and height vertically. 7. All hidden lines are show~ in dOttcldlines for easy understanding. 8. First draw the ooseof thes~Feand then construct the drawing over it. For structure~l,draw 5.00 x 5.00 meters square base and then construct the parts over it. $iJPilarly~f.Qr structure-2, draw 5.00 x 5.00 mete~ square base,with cut comers and then construct the parts over it. This way it is '. easy and unambi~~$.' 9. Any doubts can~~.~~are
Drawing Method Steps 1. Draw to scale 1:10 (or) or em

= I meter

as shown, otherwise choose any convenient scale.

2. All measurements are given in centimeters. 3. Table and Chair drawn in an Isometric View are drawn again in Axonometric View with the same scale, so that comparison can be made. Such a comparison will help to decide which ~iew is good for presentation. 4. Take a corner point and take angular lines of 45° on both sides. 5. For Table: (a) Draw a box of L x B x H =90 x 45 x 73 ems. (b) Draw the top band of 15 em. and bottom band of 5 em. (c) Draw the legs, and remove the unwanted lines for the view of the table. 6. For Chair: (a) Draw a box of L xB x H = 45 x 45 x 43 ems, which forms the seating portion of the chair. (b) Draw the top band of 5 em. and bottom b~d of 5 em. (c) Draw the legs. (d) Add the back rest of L x B x H = 45 x 5 x 45 ems. (e) Draw the net portion in the centre Lx B = 35 x 35 ems. for the seat and the back rest. Then remove the unwanted lines for the view of the chair. 7. It is very useful to practise axonometric views of different tables and chairs.

A. General assumptions 1. The bed room drawn in isometric view is drawn again in axonometric view with the same scale, so that comparison can be made. Such a comparision will help to decide which view is good for presentation. The axonometric view of the bed room shows more vertical depth than . isometric view.. 2. Length and width of the bed room (inner dimensions) 400 x 300 cms (or) 4.0 x 3.0 meters. 3. Height of the bed room Jrom floor level 300 ems (or) 3.0 meters. 4. Depth of the wardrobe on the left side 60 ems. 5. Window sizes:

=

= =

(a) Beside the wardrobe B x H

(b) Behind the bed B x H 6. Bed: (a) Size Lx B x H

= 200

= 120 x

120 ems (or) 1.2 x 1.2 meters.

=90 x 120 ems (or) 0.90 x 1.2 meters. x 200 x 20 ems (or) 2.0 x 2.0 x 0.20 meters.

(b) Support below the bed L x B x H= 200 x 120 x 20 ems (or) 2.0 x 1.2 x 0.20 meters. 7. Side cupboards: . .. . (a) Beside the bed on both sides Lx B x H =50 x 40 x 30 cms (or) 0.5 x 0.4 x 0.3 m. , , (b) Extreme corners on beth sides Lx B x H 50 x 40 x 70 ems (or) 0.5 x 0.4 x 0.7 m.

=

(c) Support below the cupboards

Lx B x H

= ioo

x 30 x 10 ems (or) 1.0 x 0.3 x 0.1 m.

=

8. Size of floor tiles Lx B 25 x 25 cms (or) 0.25 x 0.25 meters. 9. Actual measurements to the required scale should be used for the drawing.

B. Drawing method Steps 1. Draw to scale I :40 (or) 10 cm

=4 meters

.

as shown, otherwise choose any convenient scale.

2. Fix the centre point and take 45° angle on either side. 3. Draw the.outer dimensions and height of the bed J:OOmwith windows and wall thickness of 25 cms. 4. Then draw the bed with side cupboards with actual heights measured to scale as given above. 5. Draw the wardrobe as per the measurements. 6. It is essential to visualise the, room before drawing. 7. Axonometric view is another effective and easy way of communicating

interior design ideas.

THREE DIMENSIONAL

95

VIEWS

4. PERSPECTIVE (ONE-POINT) (a) Object A. In one-point perspective method, the objects are placed with 'one side parallel to the picture plane. It is useful for interior views because three walls, ,

floor and ceilingcan be shown.

'

B. Drawing method Steps I. Draw to scale 1:30 (or) 10 cm

= 3 meters

as shown, otherwise choose any convenient scale.

2. Dimensions of ~ square object are length: 1.0 m., width: 1.0 m., and height: + 1.0 m. 3. Place the plan o~he object on the picture plane (PP) as shown. 4. Fix the stationary point (SP) on PP and move it ,to a convenient distance to get the desired view. It is assumed as 3.8 m. 5. Fix the ground level (GL) of the object anywhere above the SP. It is assumed as 1.1 m. 6. Mark 1.65 m. above GL and draw horizdn line, because 1.65 m. is the nonnal eye level of a perso... .

7. 8. 9. 10.

,

Fix the vanishing point (VP) on SP line because, the object is viewed from this angle. All the elevation heights should be taken vertically from the GL. All the angular lines should be joined to VP. For all the vertical lines orthographic projections of the intersecting points on PP should be taken. These points can be obtained by joining the corner points of the object to SP.

THREE DIMENSIONAL

VIEWS

97

(b) Structure Drawing Method Steps 1. Draw to scale 1:30 (or) 10 cm 3 meters as shown, otherwise choose any convenient scale. 2. Place the plan of the structure on the picture plane (PP) as shown.

=

3. Fix the stationary point (SP) on Pp, and move it to a convenient distance to get the desired view. It is assumed as 3.4 m. 4. Fix the ground level (GL) of the structure anywhere above or below SP. It is assumed as 2.6 m from PP. 5. Mark 1.65 m above GL and draw horizon line (HL) because 1.65 m is the normal eye level of a person. 6. Fix ,the vanislj1g point (VP) on SP line because the structure is viewed from this angle. 7. All the eleva'n heights should be taken vertically from GL. 8. All the angular lines should be joined to VP. 9. For all the vertical lines orthographic projections of the intersecting points on PP should be taken. These points are obtained by joining the wrner . points of the structure to SP.

THREE DIMENSIONAL

VIEWS ~

99

:"

(c) Bed

Room

A. General assumptions 1. 2. 3. 4.

The bed room drawn in Isometric and Axonometric views is drawn again t() the same scale in this exercise for comparison. The length and width of the bed room are 400 x 275 cms (or) 4.0 x 2.75 meters excluding wall thickness and wardrobe. Height of the bed room from floor level is 300 cms (or) 3.0 meters. Depth of the wardrobe on the left side is 60 ems.

5. Windows: (a) WI

(b) Wz

6. Door: (a) DI

=90 x 120 cms (or) 0.90 x 1.20 meters. = It x 120 ems (or) 1.20 x 1.20 meters. = 100 x 200 ems (or) LOOx 2.00 meters.

7. Bed:

=

(a) Size Lx B x H 200 x 200 x 20 ems. (or) 2.0 x 2.0 x 0.2 meters. (b) Support below the bed L x B x H 200 x 120 x 20 cms. (or) 2.0 x 1.2 x 0.2 meters. 8. Side cupbOards: (a) Beside the bed on both sides Lx B x H 50 x 40 x 30 cms.. (or) 0.5 x 0.4 x 0.3 meters. (b) Extreme comers on both sides Lx B x H = 50 x 40 x 80 ems. (or) 0.5 x 0.4 x 0.8 meters. 9. It is as~umed that one wall is removed for viewing the room from a distance.

=

=

B. Drawing method Steps 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

Draw to scale 1:40 (or) 10 cm = 4 meters as shown, otherwise choose any convenient scale. Draw the plan as per the measurements and place it on the picture plane (PP) Choose the stationary point (SP) in the centre of the room on the PP line. Move the SP to a convenient distance to ga the desifed view. It is assumed as 10 m. from PP. Fix the ground level (GL) of the bed room anywhere above or below SP. It is assumed as 4.0 m from PP. Mark 1.65 m. above GL and draw horizon line (HL) because 1.65 m. is the normal eye level of a person. Fix the vanishing point (vP) on SP line because the bed room is viewed from this angle. Draw the outer frame ABCD by dropping the lines from PP. First take the back wall of the bed room comers and join them to SP. These angular lines cut PP. Take orthographic projections from these points and bring them down to GL. Join the comers ABCD to VP. They cut these dropped lines. Join all the cutting comer points. ThUS\the comers of the bed room are formed. Similarly join all the comers in the bed room plan, as shown, to SP. These lines cut PP. Take orthographic projections from these points to GL as shown. Joining of these comers to SP is not shown because of the shortage of space. It should be placed 10m. from PP as per the scale. All elevation heights should be taken vertically from GL on AD or BC lines. All angular lines should be joined to VP. For all vertical lines orthographic projections of the intersecting points on PP should be taken. These points are obtained by joining the comer points

. in the bed room to SP. 15. A single line perspective is drawn to show the details of drawing for easy understanding. Other details and presentation rendering can be done on this drawing.

THREE DIMENSIONAL

101

VIEWS I

.

5. PERSPECTIVE (TWO-POINT) (a) Object A. Two point perspective is widely used for buildings. It

~

be taken from any viewpoint by t~rning the plan to the desired position on the picture plane. It IS easy to construct and gives true photographitimage.

B. Drawing method Steps 1. Draw to scale 1:30 (or) 10 cm

= 3 meters

as shown, otherwise choose any convenient scale.

2. Dimensions <j the square are length: 1.0 m., width:

1.0 m., and height: + 1.0 m.

3. Place the pla~f the object on the picture plane (PP) in the desired angle. It is assumed as 45°. 4. Fix the stationary point (SP) on PP. Normally the point touching the PP is taken as SP. 5. Move the SP to a convenient distance to get the desired view. It is assumed as 3.5 m. 6. Take the same angle of the object to locate the vanishing point VP (left) and VP (right) on the horizon line. It is assumed as 1.0 m. from PP. Horizon line should be placed conveniently for the view. 7. Take 1.65 m. distance below thel1orizon line (HL) to fix ground level (GL) because 1.65 m is the normal eye level of a person. 8. All the elevation heights should be taken on the SP line, which divides the object vertically. 9. All left side angular lines should be joined to VP (L) and all right side angular lines to VP(R). 10. For all the vertical lines orthographic projections of the intersecting points on PP shouid be taken. These points are obtained by joining the corner points of the object to SP.

THREE DIMENSIONAL

VIEWS

103

(b) Structure Drawing Method Steps ,

1. Draw to scale I :30 (or) to cm

= 3 meters.

as shown, otherwise

choose any convenient

scale.

.

2. Place the plan of the structure on the picture plane (PP) in the desired angle. It is assumed as 45°. 3. Fix the stationary point (SP) on PP. Normally the point touching the PP is taken as SP. 4. Move the SP ,to a convenient distance to get the desired view. It is assumed as 6.0 m.

.' 5. Take the same angle of the structure to locate the vanishing points VP (left) and VP (right) on the horizon line, which is assumed as 0.90 m from PP. These VP p'nts should be placed conveniently for the view. 6. Take 1.65 ~distance below the horizon line (HL) to fix ground level (GL), becjluse 1.65 m. is the normal eye level qf a person. 7. All the elevation heights should be taken on the SP line, which divides the structure vertically.

j!

8. All left side angular lines should be joined to VP (L) and all right side angular lines to VP (R). 9. For all the vertical lines orthographic projections of the intersecting points onPP should be taken. These points are obtained by joining the corner points of the structure to SP.

THREE DIMENSIONAL

VIEWS

105 (C) Bed

I I

Room

B. Drawing method Steps 1. 2. 3. 4. 5. 6. 7.

=

Drawing to scale 1:40 (or) 10 cm 4 meters as shown, otherwise choose any convenient scale. Draw the plan as ~tthe measurements and place it on the picture plane (PP) at an angle of 45°. Choose the stationarypoillt (SP). Normally.the comer touching the PP line is taken as SP. Move the SP to a convenient distance to get the desired view. It is assumed as 10m. from PP. Fix the ground level (GL) of the bed room anywhere above SP. It is assumed as 4.5 m from PP. Mark 1.65 m. above GL and ,draw horizon line (HL) because 1.65 m is the normal eye level ofa person. Locate conveniently for viewing the vanishing points VP (left) and VP (right) on the horizon line. It is assumed as 8 m. from SP line to the left for VP (L), and 8 m. from the SP line to the right for VP (R). 8. All the heights should be taken on the SP line from GL. 9. All left side angular lines should be joined to VP(L) and all right side angular lines to VP (R). .

10. For all the vertical lines orthographic projections of the intersecting points on PP should be taken. These points are obtained by joining the comer points of the structure to SP. 11. First, take the outer comers of the room and then the inner comers of the room and join them to SP. Take orthographic projections from these cutting points on PP and form the outer walls, floor and ceiling. 12. Then, take the inner comers of the room and join to SP. Take orthographic projections from these cutting points on PP and form the windows, bed, wardrobe and side cupboards. 13. Always remember to take the actual scale heights on the viewing line i.e., SP line. Try to form the top and bottom of all items by joining to VP (L) and VP (R). With some practise this method can be understood. The earlier exercises should help in doing this. The dotted lines are clearly shown to understand this method. 14. Single line perspective is drawn to show the details of theudrawing for easy understanding. Pres!":nt"t;nn rpn-t :-~ M- 10...-tnnp nn this drawing.

1. ORGANISATION OF SPACE Organisation of interior space is very important in interior. design. Proper use of space for various activities leads to better functioning and beauty. Economic utilisation of space is very important in modem interiors. There should be minimum circulation area and best use of available space for the activity' to be performed, To achieve this, proper indoor furniture arrangement is necessary. In commercial interiors, every cubic meter of orea may' have monetary . . value. For-.prQ~r organisa~io~ of interior space the following points may be. noted. 1. Proper proportion and consi~tency in indoor furniture. 2. Minimum number of doors and partitions for free flow of space and spacious look. 3. Continuity of flooring by using same colours.>f'6rtiles and carpets.

4. Using suitable indoor plants. 5. Selecting'limited

. .

variety of texture~ and patterns.

- 6. Selecting limited variety of colours. 7. Using cool colours. 8. 9. 10. II.

Provide built-in furniture as far as possible. Provide adequate natural and artificial light. Choose minimum number of furniture items. First, the
.

INTERIOR DESIGN METHOD

109

2. INTERIOR LAYOUTOF A RESIDENCE A. Index 1. Verandah 3. Dining 5. Master bed room 7. Common toilet

B. Built-up area excluding verandah 91.04 sq. m. C. Door.and Wint' sizes: 1. Doors

2. Living 4. Kitchen 6. Attached toilet 8. Childrens bed room

(a) Entrance door (b) Toilet doors (c) All other doors

Height x Width 200 x 120 ems. 200 x 80 ems. 200 x 100 ems.

2. Windows ~ Ventilators (a) Window WI (b) Window W2 (c) Window W3 (d) Window W4 (e) Ventilator VI

Height x Width 120 x 120 ems. 120 x 100 ems. 100 x 120 ems. 120 x 60 ems. 50 x 100 ems.

D. Arrange the followingfurniture. 1. Verandah: (a) Arrange outdoor plants.

2. Living: (a) L-shaped sofa. (b).Circular table 80 em. diameter. (c) Plant turf 50 em. diameter. (d) Partition wall between living and dining upto door level. 3. Dining: (a) Dining table, length x breadth = 150 x 80 em. (b) Six chairs each, length x breadth

=50 x 40 em.

(c) Suitable wash basin near the toilets.

4. Kitchen: (a) Sink & drain board (b) Stove (c) Fridge (d) Cupboards 30 em. wide (e) Cooking platform 60 em. wide

INTERIOR DESIGN

110

5. Master bed room: (a) Single bed, length x breadth x Height

= 200 x 200

(b) Built-in wardrobe, length x breadth x height (c) Corner shelf.

PRINCIPLES AND PRACTICE

x 40 em. with side cupboards of 30 em. width.

= 150 x 60 x 300 em.

6. Attached toilet: (a) Wash basin (b) Western WC (c) Bath space 7. Common toilet: (a) Wash basin (b) Indian WC (c) Bath space 8. Childrens bed room: (a) Two beds each, length x breadth x height 100 x 200 x 40 em. with side cupboards. (b) Built-in wardrobe, le1!gth x breadth x height = 150 x 60 x 300 em.

=

(cYCorner shelf.

E. Wherever scale measurements are .not given, suitable assumptions may be made Drawing Method Steps 1. Draw to scale: 1:50 (or) 2 em

= 1 meter

as shown, otherwise choose any convenient scale.

2. Draw the ground floor plan as per the given measurements. '3. AlTange the indoor furniture as shown leaving suffici~nt circulation area. 4. While drawing the indoor furniture observe the circulation areas marked with arrows. Minimum circulation area without obstructions shows efficient interior design layout. 5. In designing any interior space this aspect of efficient utilisation of space should be given due care.

INTERIOR DESIGNS PRINCIPLES AND PRACTICE

III

3. INTERIOR DESIGN METHODOLOGY A scientific method can be adopted for designing interiors. This methodology can be broadly divided into four stages and thirteen steps. Every interior design scheme should go through these four stages for a comprehensive understanding of its usefulness.

STAGE I. It may be divided into four major steps. They are Interior design purpose, Activity performed, Activity details and Activity diagram. I. Interior design purpose: There should be a basic reason to design an interior. The reason could be to organise the commercial needs, official needs, residential needs etc., The real purpose of organising an interior should be clearly defined in the beginning. This basic purpose should form the core of interior design and all related actions should revolve around it. 2. Activity performed: Once the purpose of an interior is decided, then the activity to be performed should be clearly discussed with the client. For example: if the client wants to have an interior design for an office, then how that activity is normaIly performed should be discussed. The entry, exit, various activity units, tables, chairs and other furniture requirement should be discussed in detail. 3. Activity details: Then, the details 9f an activity to be performed in the proposed interior should be worked out. For example: the number of tables, chairs, storage units, lights, fans, AC units and other minor details should be enumerated. These details should be prepared in close consultation with the client. 4. Activity diagram: Based on the above discussions with the client, an Interior Designer should prepare an 'Interior Activity Diagram' showing the flow and organisation of space into various units. This is the crucial diagram based on which the entire interior design should be prepared. An Interior Designer can be innovative and creative in organising these spatial units. STAGE II. It may be divided into four major steps. They are Design process, Concept plan, Revised concept plan and Final plan. 5. Design process: Based on the Stage-I details, an Interior Designer should start the interior design process. In this process, an Interior Designer can give fuIl freedom to his thinking and creative abilities; there are no limitations and restrictions. The real ability and creativity of an Interior Designer is revealed in this process. 6. Concept plan: Concept plan is the basic idea of an Interior Designer. An Interior Designer should present this idea in a effective way to convince the client. It can be presented in a pictorial form or written form or both. It would be appropriate to have a combination of pictorial and written forms of presentation. The drawings and language should be simple and clear, so that everybody can understand easily. Before awarding the work, the client always tries to perceive the conviction and confidence of an Interior Designer in the presentation of the ideas. This concept plan should be thoroughly discussed with the client. 7. Revij'ed concept plan: After thorough discussions with the client, an Interior Designer should m~e the necessary changes to accommodate the clients ,views. Thus the revised concept plan may be prepared. The concept plan can be revised any number of times until the client is totaIly convinced that the requirement is satisfactorily met in the concept plan and gives the approval. The final revised concept plan beco~ the basis for detailed .

drawings.

,:

.

8. Final plan: Based on the revised concept plan, the detailed drawings should be prepared to as<;ale. Here the Computer Aided Drafti"ng (CAD)

packages are very useful for easy and quick drafting, and also to incorporate future changes. These details may include all, work~ng drawings, estimates, bill of quantities, specifications, tenders etc., AIl the details on interior design should be prepared, keeping in mind easy and efficient execution of work. STAGE III. It may be divided into three major steps. They are Execution & supervision, Incorporating changes and Completion of work. 9. Execution & supervision: Once execution of work starts, an Interior Designer should make periodic visits t
.

114

INTERIOR DESIGNS PRINCIPLES AND PRACfICE

cannot visuslise things in the drawings. Periodic site visits by an Interior Designer and the client is necessary for satisfactory execution of the work. 10. Incorporating changes: An Interior Designer and the client can improve the interior during the site visits, if they find something is lacking. These on-site improvements may enhance the outlook of an interior. These changes should be incorporated during the course of work, but they should not go beyond the stipulated time and budget unless under exceptional circumstances. II. Completion of work: The closing stages of the work are as important as the beginning. An Interior Designer tend to ignore the work while it is nearing completion, which is a bad practice. An Interior Designer should ensure that the work is executed precisely as per the plan with special care for safety mt,asures, emergency provisions and compliance of local building regulations. A check-list may be prepared to know whether all the works .

are carriedout satisfactorilyor not. A successfullycompletedinteriorprojectis a creditto all thoseinvolved.

STAGE IV. It may be divided into two major steps. They are Evaluation and Feedback. 12. Evaluation: Evaluation studies are the most neglected part of interior design because most of the interiors are designed, executed and forgotten. Nobody takes the interest to do a scientific evaluation study after completing the project. The results of these evaluation studies serve as feedback to similar projects in future. Once an iJ!terior is completed and put to use, a primary survey should be conducted atleast after one year to know whether the essential purpose of the interior design is served or not. This survey should be scientific and based on users needs. 13. Feedback: The survey results should be scientifically analysed and the results should be recorded for future use. Many of the creative interior design concepts may satisfy the ego of respective interior designers, but ultimately it is the users who should appreciate an(j accept. These feedback results of various interiors form a reservoir of knowledge for,pther young interior designers to learn and improve their design. EXERCISE i

1. 2. 3. 4. 5. 6. 7. 8. 9.

Draw front elevation. Draw any two cross sections. Prepare the electrical layout. Prepare the plumbing layout. , Design and draw the details of the paJ1.itionbetween the living and dining area. The partition should serve as curio shelf for the living area and as crockery shelf for the dining area. Design and draw the details of the built-in wardrobes in the bed rooms. Work out the interior details of the kitchen. Draw one-point perspective of any room. Describe the various stages of interior design methodology.

The electronic computer is one of the most remarkable modem instruments in human history. The computer with the developments in electronics is taking us into an information ,technology 'revolution. Due to this revolution powerful micr
drawing purposes." .

Architectural

.

and Interior Design drawings are an integral part of building construction for the past many years. It is the link between design and

construction. Information is quickly communicated to the site of building construction in the form of drawings prepared as per the required designs. It is believed that a picture or drawing is worth more than thousand words for communication. The speed of graphic comprehension can reach as high a rate as 50,000 times that of reading. An interior design drawing is prepared by using drawing instruments. The recent alternative is to prepare the drawing with the aid of computer. This method is known as 'Computer Aided Drafting (CAD)'. Most of the computer aided drawing packages can be learnt easily even without any computer operating experience. It is because of the fact that they are basically menu driven. There are four fundamental elements of a drawing. They are: I. Points 2. Straight tines " 3. Arcs 4. Curves In a computer aided drawing system the points c~ be located by selecting the position with the curser, snapping the grid points or' by entering the numerical values of the co-ordinates of the points. There are many lJseful functions employed in a CAD system, which are not possible manually.

116

INTERIOR DESIGN PRINCIPLES AND PRACTICE

1. FACILITIES IN CAD SYSTEM (a) Scalil/g - To enlarge or diminish the si7.e of a displayed drawing without changing its shape. To enlarge or reduce a selected area of the drawing seen 9n the scr~n. . (b) Zoomil/g (c) Tral/slatil/g - To move. parts of a drawing and redrawing them in a new position to a chosen scale. (d) Rotatiol/ - To rotate the features around a selected centre and redrawing them at the new position. (e) Mirroril/g - To reverse the image or drawing on the chosen line of symmetry. (j) Duplicating - Copying a feature or component many times and displaying it in an orderly manner. ~

2. ADVANTAGES OF USING CAD (a) Construction of quality drawings is possible. The quality of lines, dimensions, symbols etc.,doe$--not

draughtsman.

depend on the individual skill of the

.

-, (b) Database can be created, which will be useful for retrieval and easy access. for others. . (c) Storage library can be created with commonly used architectural, building, elettricaland other components. These can be ~Wnand memory and recalled as and when required. They can be positioned anywhere on the screen and drav;p to the required scale and: angle. (d) Different layers can be used as a stack of transparent sheets. They maybe made together as a'complete drawing as required.: (e) High level of dimensional accuracy can be obtained. '.' o' (j) Drawing can be edited easily. COlTection of mistakes, copying, moving, deleting and inserting can be done quickly and easi!y.

stored in

The speed and ease with which a drawing can be prepared and modified with the help of a computer offer a great time saviM'advantage over manual drafting of drawings. There are some drawing software packages'in the market. To understand CAD in detail, we shalldiscuss')x;lOW AutoCAD; which is a very popular drawing software package released by Autodesk Ltd. USA.

3. AUTOCAD (REL. 10) DESIGN SOFTWARE PACKAGE The Auto CAD design software package is a general purpose Computer Aided DesignlDrafting application for the computer: There is virtually no limit to the types of line drawings that can be prepared by using Auto CAD. The following are some of the applications for which Auto CAD is being used. * Architectural drawings of all kinds. * Interior design and facility planning. Work flow charts and organisational diagrams. * Proposals and presentations. * Graphs of all kinds. * Drawings for electronic, chemical, civil, mechanical, automotive and aerospace engineering applications. * Topographic maps and charts. * * Yacht designs. * Theatre set lighting designs. * Musical scores. * Technical illustrations and assembly drawings. * Company logos. * Greeting cards. * Line drawings for the fine arts. The applications do not stop with static images. When used in conjunction with Auto SftADE rendering and AutoFLIX animation programme},AutoCAD forms the basis for movie like presentations and interactive displays. .

.

INTRODUCTION

TO COMPUTER AIDED DRAFfING

(CAD)

1J1

A. OVERVIEW AutoCAD provides a set of entities for use in constructing the drawing. An entity is a drawing element such as a line, circle or test siring; To t~ll AutoCAD which entity to draw, you type a command (for instance 'CIRCLE') .0P the keyboard or select it from a menu. Then, re~ponding to prompts on the screen, you supply parameters for the chosen entity. These parameters always include the location in the drawing where you want the entity to appear; sometimes a size or rotation angle is also required. After you supply this information, the entity is drawn and appears on the screen. You can then enter new command to draw another entity or perform another AutoCAD function. The effect of every change you make appears immediately on the screen. Other AutoCAD functions let you modify the drawing in a variety of ways. You can erase or copy the entities as required. You can change the view of the drawing displayed on the screen or display information about the drawing. It also provides drawing aids that help you position entities accurately. When you want a paper copy of your drawing, you can plot it with a pen plotter or printer plotter. AutoCAD command format allows you to do all these functions easily. You can enter commands by typing on the keyboard or by using a mouse to select choices from a menu. B. CREATING THE DRAWING The following concepts and terms introduce the main elements of an AutoCAD drawing. They will become familiar as you create your own drawing. '-..

(a) World co-ordinate

system

AutoCAD uses cartesian co-ordinate system to locate points in the drawing. The 'X' axis indicates' horizontal distance and the 'V' axis indicates vertical distance. The origin is where the values of 'X' and 'V' are both zero. This is taken as the World Co- ordinate System (WCS). A point is expressed as an (xy) co-ordinate. To locate a particular point in the World Co-ordinate System, you can imagine a perpendicular line crossing the 'X' axis at the X points value and another crossing the 'V' axis at the Y points value. The point is located where the two lines intersect. Another way to visualise this is to imagine a rectangular grid emanating from the co-ordinate systems origin. To locate a point with the grid co-ordinates (5,4) you would count 5 grid lines to the right from the origin (the positive X direction) and 4 grid lines up (the positive Y direction) For two-dimensional drafting, all work can be done using (X, Y) co-ordinates. However, if the work involves three-dimensional drafting or modelling the Z'axis can be added to locate 3 D points using an (X Y Z) co-ordinate triple. The Z axis is at right angles to the plane defined by the X and Y axes (also called the XY plane). When AutoCAD expects you to enter a 3D point, you can often enter just an (x, y) co-ordinate pair, omitting the Z value. AutoCAD will fill in the value you have establis~d as the current elevation. Since pointing devices supply only 2D co-ordinates, AutoCAD always uses the current elevation as the Z value for points you enter. The XV plane at the current elevation is called the construction plane. . (b) Drawing units and scaling The distance between two co-ordinates is measured in drawing units. For example, if you draw a line between the co-ordinates (1, I) and (1,2) it measures simply one unit in length. A line drawn between the co-ordinates (1, I, 0) and (1, 1, I) is also one unit in length. There is no need to restrict to integers only. AutoCAD drawing database retains at least 14 significant digits of precision for each point, so you can place an object at the point (507, 841142, 0.(038059) if you like.

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INTERIOR DE~IGN PRINCIPLES AND PRACTICE

A unit can correspond to whatever form of measurement your drawing requires. It can be inches, feet, centimeters or w~atever according to the drawing requirement. Thus you can draw using 'real world' units and eliminate the possibility of M:aling errors. When the drawing is complete, you can plot it at whatever scale you like. In fact. you can plot a given drawing (or parts of it) at several scales, eliminating the need for separate drawings at different scales, Auto<;::AD lets you choose among several formats for the display and entry of co-ordinates and distances. For e~ample, you can choose 'feet and fractional inches' for interior design drafting; other possibilities include scientitic notation and engineering formats. Simitarly, you can select the format used for display and entry of angles; decimal degrees are the norm, but you can choose grades, radians, degrees/min~tes/secotlds or surveyors units. (c) Drawing entities

,

Drawing with AutoCAD consists of positioning entities at co- ordinate locations. An entity is a predefined element that you place in a drawing by means of a single command. Lines, arcs and circles are entities used frequently. Text. attributes and dimensions are also entjties in AutoCAD drawings. The following table describes the entity types offered by AutoCAD: * Line * Arcs & Circles * Text * Traces * Solids * Shapes * Blocks * Attributes * Dimensions * Polylines * 3D Polylines * 3D Faces' * 3D Meshes

:

Lines can be drawn with various dot-dash when drawing a line segment, you can vrovide either 2D (xy) co-ordinates or 3D (xyz) co-ordinates. . Arcs and Circles can be drawn with various dot-dash line types. Several method\J are provided for drawing arcs and circles. Points can appear as dots, squares, circles or any combination of these. You car(locate point entities co-ordinates. Text can appear in a variety of founts, with any size and orientation you wish. In addition can create text styles to apply mirroring, obliquing or a horizontal expansion or compression factorto the teit characters. Traces are two dimensional, solid filled lines of any width you specify. Solids are two dimensional, solid filled triangular or quadrilateral objects. Shapes are small objects you can define outside AutoCADand place in tIfe drawing with a specitied scale and rotation. Blocks are compound entities formed from groups of other entities. Attributes attach constant or variable text information to each instance of a block. You can choose whether they are visible or not. Dimensions are compound enti~ies sImilar to blocks. containing all the lines, arcs, arrows and text comprising a dimensioning annotation. Polylines are 2D connected line and arc segments with optional dot-dash line types, width and taper. Commands are provided to construct ellipses, regular polygons, filled circles and 'doughnuts' using polylines. 3D polylines are fully general three dimensional objects composed of straight line segments. 3D Faces are three dimensional triangular or quadrilateral plane sections'. 3D Meshes are three-dimensional polygon meshes. You can specify the size ofthe mesh and the lo~on of its vertices, Commands are provided to construct ruled surfaces of revolution and tabulated cylinders using 3D Meles. I

Each entity can be drawn at a specitied elevation (a Z distance above or below the XY plane of the current UCS). In addition many entities can be given a thickness; that is, they can be extruded a specitied amount. Entities always extrude in the positive direction of the Z axis (called as the extrusion direction) of the UCS in which the entity was created. To check the positive direction of the Z axis, use the right hand rule. (d) Colours and Line types

You call assign a colour and a line type to each entity. The colour is a number from I to 255 that selects the actual colour in which items are drawn on the graphics monitor. A line type is a specific sequence of alternating line segments and spaces. Using these properties, you can draw attention to important details in your drawing, highlight recent changes or depict the relationships amount entities. (e) Layers You can assign various portions of the drawing to different layers and define as many layers as you like. The layering concept is similar to the transparent

INTRODUCTION

(h) Freehand

TO COMPUTER AIDED DRAFfING

(CAD)

119

sketching

AutoCAD has a facility of sketching. You can draw short, connected lines freehand with a pointing device, allowing you to trace maps 01' add yom signature to a drawing. (i) Zooming and Panning You can magnify or shrink the visual image of the drawing on the screen. Magnifying the image is called 'Zooming in', shrinking it is cal~d 'Zooming out'. When you 'zoom out', you can see a large portion of the drawing; 'zooming in' can blow up a small portion of the drawing and show more of its details. You can 'zoom in' to draw intricate parts of your drawing with exacting details and then 'back off' to look at the finished drawing. AutoCAD zoom ratio is about ten trillion to one, more than adequate for most applications. The graphics screen is used as a window through. which you can look at aJI or part of your drawing. Keep in mind that co-ordinates refer to fixed locations in the drawing and not to the physical location on the display screen. Therefore, the absolute size ofa unit remains constant; the points (1, I) and (I, 2) are always one unit apart, although the apparent distance between points on the screen varies with different zoom levels. When you 'zoom out' the distance between points on the screen varies with ditterent zoom levels. When you zoom out, the distance between co-ordinates appears to be small. A line drawn between (I, I) and (I, 2) may be only a quarter inch long measured on the screen. When you zoom in, the distance between co-ordinates appears ~arger, so the one-unit line may appear to be several inches long. In both cases, the absolute distance between the co-ordinates is

constant. Only the screen display changes.

.

.

You can pan across the drawing in any direction. Panning allows you Loview a different portion of the drawing without changing its magnification. A line drawn from (1, I) to (1, 2) can thus appear in different locations on the screen. (j) Display extents When you zoom or pan, AutoCAD keeps track of the current screen location by maintaining a set of horders called the display extents. These are the borders of the current display expressed in XY drawing Co-ordinates. Zooming and panning (,'hange the display extents. When these changes occur, the drawing as regenerated or redrawn to show only the portion bounded by the new display .extents. (k) Plan view ami 3D views The term plan view derives from the view you see in an architectural floor plan. In AutoCAD. it is a view 01 a spccifit~d User Co-ordinate System (UCS) from a position directly above the origin of its construction plane (i.e.. a view point of (0, n, I). In a plan view,tht~ l'onsl,uctiOl:j piane of the current ues i~ parallel to the screen, You can also view your drawing from any poim in ~pacc (c\cn from inside an object!.

120

INTERIOR DESIGN PRINCIPLES ANIJ PRACTICE

(1) View ports You can divide the graphic area of the screen into several view ports, each of which can display a different view of the drawing. Panning and zooming. can be performed in each view. port independently. (m) Editing the drawing The editing facilities of AutoCAD make it easy to correct or revise a drawing. For example, you can move an obje.ct to a new location, put in on a different layer, or erase it. H you want it back, one command restores it instantly. Multiple copies of an object, arranged in rectangular or circular manner. Its other editing functions are rotating, enlarging, shrinking or stretching objects, trimming or extending one object to meet another precisely, dividing an object into equal parts, creating an objects mirror image and drawing fillets or chamfers between two objects. You can change the location or size of an object by dragging it. Some editing functions are specific to -certain entities: you can split Lines, Traces or Arcs. You can delete parts of circles and edit Polylines to fit curves or splines to them. You can also explode Polylines and other complex entities and transform them into individual simple entities. You can add cross-hatching or patterns to objects. optionally. scaled and rotated. There are many options for adding dimension annotations: it can draw linear and angular dimensions. It can automatically calculate the dimension measurements and position the dimension arrows and text. After editing,' it will automatically recalculate:
entry

You can specify points in the drawing in several ways using either the keyboard or a pointing device like mouse. From the keyboard, you can designate points by typing absolute co- ordinates or co-ordinates relative to the last point specified. You can use a pointing devise to designate points. Designated points can be locked (snapped) to a user-defined grid to ensure accuracy. It can also lock onto various entity features such as the midpoint of a line or the centre of a circle. You can also enter commands in several ways. You can type a command directly or select a command from any of the menus like screen menu, Tablet menu, Pull down menu and Icon menu. (p) Open architecture An open architecture approach allows to customise and extend many of AutoCAD features to suit your requirements. You can Define your own screen and menus to automate the operations you perform frequently. Create script files to automate lengthy command sequences. Define your own text fonts. Define your own dot-dash line types. Define your own batch patterns. Create custom symbols and libraries. Customise the HELP files. * Use DXF or IGES files to transmit your drawing geometry to other programmes for analysis ot to create drawings from data generated by other * programmes. * Generate slide files from your drawings for incorporation in documents produced with desk-top' publishing- software. Execute external programmes while editing a drawing. * * * * * * *

I~TRQDUCTION

TO COMPUTER AIDED DRAFTING (CAP)

121

Use AUTOLISP to perform calculations, automate repetitive tasks, create new AutoCAD commands or redefine existing commands. * If AutoCAD does not do exactly what you want, then you can stretch and mould it according to your needs.

(b) Drawing units & scaling . (d) Layers if) Views and View-ports (h) Open architecture

In the last decade there has been tremendous proQfess in science and technology. The advent of electronics and computers has enable engineers to go ahead with the projects which were considered intrackable some years back. This is because more powerful, efficient and optimum methods of analysis and design have been ensured. The development of newer materials has opened new era for construction industry. To make suitable applications of these new developments in analysis and design, the relavent codes have been changed from time to time. It is with the above aim in mind that in the present publication, the authors have tried to present the "Design of Steel Structures" as per latest technology, field practices and new construction techniques. Special attention has been given to the details of connections. The major information \ in each chapter is listed as answer to objective type questions at the end of the chapters. Some i

packageprogramsfor analysisand designof sometypical problemsin steelconstruction:develop~d and used by authors over the years, have been presented. With the help of user's manual givtn in a simple language, a 'designer even without any background of the computer programming can use these packages quite comfortably. This book also caters to the needs of those appearing in various competitive exams e.g. Engineering Services. Civil Serv.ices, GATE, State Public Services Commission exams. and exams held by Semi-government agencies like ONGC. NHPC, NTPC, SPCl, IOC, Gas Authority of India etc. Answers to objective type questions generally asked in these ex::-minations have been .

highlighted. CONTENTS 11 . Introduction 1.2. Rivetted and Bolted Connections 13. Welded Connections 14. Design of Flexural Members 15. Design of Tension Members 16. Design of Compression Members 17. Column Bases 18. Design of Trussed Roofs

1. 2. 3. 4. 5. 6. 7. 8. 9. Design of Plate Girder 10. Industrial Buildings Pages: App. 850 + XVI

Plastic Design Steel Tanks Aluminium Structures Steel Bridges Transmission Tower~ Steel Chimneys Cold FQrmed Light Gauge Steel Members Structural Timber Appendices 1-.10

PLANNING AND DESIGN OF RESIDENTIAL BUILDINGS [MODERN BUILDING DESIGNS] By: Y.N. RAJA RAO{-Architect