green buildings

Prepared by Prashanth J.

PLANNING OF RESIDENTIAL BUILDING SYSTEMS

INTRODUCTION

As per National Building Code of India (2005), a building is defined as, “Any structure for

whatsoever purpose and of whatsoever materials constructed and every part thereof whether

used as human habitation or not and includes foundation, plinth, walls, floors, roofs,

chimneys, plumbing and building services, fixed platforms, verandah, balcony, cornice or

projection, part of a building or anything affixed thereto or any wall enclosing or intended to

enclose any land or space and signs and outdoor display structures.” All buildings exert direct

or indirect influence on the people who use the buildings as well as who see the buildings.

The direct influence is judged from the feedback as to how far the building is making its

occupants comfortable, healthy and cheerful. The indirect influence is far and reaching as it

not only affects the occupants of the building but also the people who see the building from

the outside as it forms a part of overall development and landscape. The topographical

features of the site with natural and artificial surroundings are to be taken into account while

planning and designing a building.

Types of buildings

As per National Building Code of India (2005), buildings are classified as,

a. Residential buildings. e. Business buildings.

b. Educational buildings. f. Industrial buildings.

c. Institutional buildings. g. Storage buildings.

d. Assembly buildings. h. Hazardous buildings.

RESIDENTIAL BUILDINGS

A building should be regarded as residential building when more than half of the floor area is

used for dwelling purposes. Different types of residential buildings are private houses,

duplexes, flats, apartment houses, bungalows, penthouses, Condominiums (A condominium

is an apartment that the occupant owns rather than rents) and studio house (small house

which combines living room, bedroom, and kitchenette into a single room).


Fig: Different types of residential building

SITE SELECTION FOR A BUILDING

Selection of site has an important role in planning and design of a building by the engineer

and the architect.

1. The site should preferably be situated on elevated and leveled ground. It should not be

located in a flood prone area.

2. To construct economical foundations, soil should be hard and compact with a good bearing

capacity.

3. The water table of ground at the site should not be high.

4. The site should not be irregular in shape or have sharp corners. The site should be

preferably be rectangular or square in shape.

5. Site should have the facilities such as drainage or sewer line, power line etc. Site should be

well connected to good transportation facilities for carrying materials of construction and

future transportation. It should also have facilities like school, health care, shopping centre,

banks, post office and so on.

5. Site should have good landscape so as to promote healthy and peaceful living.

6. It should be pollution free from kilns, quarries, industrial plants/ buildings emitting smoke,

steam, fumes of obnoxious odour and noise or other similar environmental pollutants.


7. The site should have unobstructed natural light and air and the building on the proposed

site should not get overshadowed from adjacent buildings.

8. The site should have clear status of the present ownership or the title of property.

PRINCIPLES OF PLANNING

The main objective of planning a building is to ensure that the different components of a

building are so arranged that the occupants can perform desired function with ease and

comfort. Good planning also requires that the entire area available within the building is

gainfully utilized, with minimum area allocated to circulation. Maximum percentage of our

buildings comprises of dwelling and as such the various principles of planning which are

given below are more relevant to houses.

The various principles which should be kept in view while planning of buildings can be

broadly summarized as under,

l. Aspect. 6. Circulation.

2. Prospect. 7. Privacy.

3. Furniture requirements. 8. Sanitation.

4. Roominess. 9. Elegance.

5. Grouping. 10. Economy.

Aspect: Aspect is meant for arrangement of doors and windows in the external walls of the

building which allows the natural gifts such as sun shine and air, scenery etc. Aspect gains

special significance in case of residential buildings. A room which receives light and air from

particular side is termed to have aspect of that direction.

For example, eastern aspect for kitchen is preferred, so that the morning sun would refresh

and purify the air and the kitchen would remain cool during latter part of the day. The living

room may have southern or south-eastern aspect. The sun is towards south during winter and

as such the living room with southern aspect would have the advantage of sunshine during

winter and obviate the sun during summer (since the sun would be on northern side or at high

attitude towards south in summer).

Similarly, the bedroom may have west or south-west aspect as the breeze required during the

summer will be available from that side. However, a verandah or a gallery, should be

provided on this side to protect the structure from hot afternoon sun and also to minimize heat

radiation during night.

Also, the reading room, store, studios, stair, class-room etc. should have north aspect since

there will be no direct sun from north side for most part of the year. Besides this, the light


from north will be diffused and evenly distributed which result in achieving desired comfort

conditions in such rooms.

Prospect: Prospect is the term used to highlight the architectural treatment given to a

building so as to make it aesthetically pleasing from outside and arranging external doors and

windows in such a manner that the occupants are able to enjoy the desired outside views from

certain rooms. The primary consideration the planning of a building are the aspect and

prospect and these both, often may be at variance with each other. Both these demand the

disposition of doors and windows in the external walls at particular places and in particular

ways. Prospect is determined by the views desired from certain rooms of the house and in

interest by surroundings peculiarities of selected site. For the good outlook natural and

artificial landscapes should be considered as a law of architecture. E.g.: Projecting of

windows.

Furniture Requirements: The functional requirement of a room is decided based on the

required furniture. Generally, non-residential buildings are planned according to furniture

equipment and other fixtures. In designing any dwelling, the architect should take the

furniture in to account which occupant will use. It is better to prepare a sketch and indicate

the position of furniture which helps position of' doors, windows, circulation space, size of

room etc.

Roominess: Roominess refers to the effect produced by deriving the maximum benefits from

the minimum dimensions of a room. Giving due importance to the furniture placement in the

room. Factors effecting of' roominess are

1. Size of the room 2. Shape

3. Furniture used 4. Position of doors, windows.

Every unit in the building is matter of cost, so we must take the maximum advantage of every

nook and corner. For storage purpose we can use cupboards, lofts, wooden shelves etc. The

size and shape of certain rooms create desirable and undesirable impressions with regard to

roominess. A square room appears smaller then the rectangular room of same area. It is also

relatively smaller in respect of utility. Better proportion of the length to breadth for good

rooms is L: B = 1.2 to 1.5: 1. If the ratio exceeds one and half, then again bad effect may be

created. A room, having its length twice the width is objectionable as it creates tunnel-like

feeling.

Grouping: We know that every apartment in a building has got a definite function and there

is some inter-relationship of sequence in between them. Grouping consists in arranging

various rooms in the layout plan of the building in such a manner that all rooms are placed in


proper co-relation to their functions and in proximity with each other. The basic aim of

grouping of the apartments is to maintain the sequence of their function according to their

inter-relationship with least interference.

For instance, in a residential building dining room should be closer to kitchen. Kitchen should

be away from W.C to avoid smell and smoke. Main bedrooms should be so located that there

is independent and separate access from each room towards the W.C. directly or through

other un-important rooms.

Circulation: Circulation is the access into or out of a room. It is the internal movement

inside a building and the area earmarked for it. It is the space used for getting comfortable

communication from one or another or from one floor to another. Circulation area should be

straight, short, bright, lighted both day and night and well ventilated. Circulation should

neither affect the privacy of a room nor interfere with the utility space. There are two types of

circulation,

1. Horizontal Circulation

2. Vertical Circulation

1. Horizontal Circulation: It is the circulation on the same floor i.e. it may be between rooms.

E.g.: Circulation between passage, corridor, halls and lobbies. Area of horizontal circulation

may consist of 20% to 25% of the total building area.

2. Vertical circulation: It is nothing but the movement of upward and downward movement.

These are normally stair cases. For multi storage structures electric lifts are provided, still

stair are necessary if there is any electric fail, or the escape exist for fire disaster. E.g.: Stair

case, lift, ramp, escalators etc. Area of vertical circulation is about 8% to 10 % of total area.

Privacy: It is one of the most important principle for planning of all types of general &

residential building. The two types of privacy are

1. Internal privacy

2. External privacy

1. Internal privacy: It is important in case of bath room & sanitary services attached bath

room, toilets, Lavatories, water closets, urinals etc. The internal privacy can be achieved by

providing lobbies or screens. All these services should be independent for every bed room

without disturbing the other. The privacy depends on the position of door.

2. External Privacy: It is nothing but the privacy of the building. If the building is exposed to

the public street or neighbour building there is no privacy for that. The entrance can be

screened with trees or suitable grid work.


Sanitation: For sanitation, we must provide proper light and ventilation facilities for general

cleaning and sanitary conveniences to maintain hygienic condition of the building. Light is of

primary significance. Sunlight destroys germs and also it provides the valuable health giving

properties of ultra violet rays in clear sun light.

Elegance: Elegance is the grand appearance of a building attained mainly owing to the

elevation which in turn depends on the plan. Without elegance even a best-panned building

may not have beauty whilst a poorly planned building, if given a slight consideration on front

portion may produce good elegance. A better elegance can be obtained by,

a. Selecting superior building materials for facing such as polished stone-granite, marble

or mosaic, glass (transparent or opaque), timber, paint and varnishes with proper

contrast.

b. Providing projections like sunshades, balconies, canopies, porch with or without

pergola openings.

c. Providing bay windows, corner windows etc.

Economy: The building should have minimum floor area with maximum utility. It will

reduce cost of construction and hence will be economical. Economy should not be achieved

at the cost of strength, otherwise the useful life of building will reduce. Economy restricts the

liberties of an architect on aesthetic development upto certain extent. Economy can be

achieved by implementing the following measures without affecting the utility and strength

of the structure.

a. Providing simple elevation.

b. Dispensing of porches, lobbies and balconies.

c. Reducing the storey height.

d. Reducing the number of steps of stairs by giving more rise to the steps.

e. By standardization of sizes of various components and materials.

PRACTICAL CONSIDERATIONS

Besides all the principles of planning discussed, the following practical points should be kept

in mind in the planning of a residential building.

1. Strength and stability coupled with convenience and comfort of occupants should be the

first consideration in planning.

2. In the years to come, a man perhaps has to add awing or extend some part of the house.

Provision for this should be made in the planning in the first instance so that some part

already built may not be required to be dismantled in future.


3. The elements of the building should be strong and capable of withstanding the adverse

effects of environmental factors that are likely to arise.

4. As far as possible, sizes of the rooms should be kept large. Larger rooms can be

shortened by providing movable partitions, but smaller rooms cannot be enlarged.

5. Life period of a building should be at least 50 years.

6. Money should not be spent unnecessarily for elaborate architectural purpose like

balconies, arches etc.

7. Use of prefabricated elements for lintels, chajjas, steps etc is preferred. This measure is

useful in affecting economy.

8. If all bedrooms are in the first floor, lifts should be provided for sick and old, at least

one bedroom should be provided in the ground floor for them.

9. The number of doors and windows should be minimum from the safety and strength

point of view and at the same time there must be sufficient numbers of windows for

ventilation, and lighting.

ACOUSTICS AND AIR REQUIREMENTS

Acoustics

The acoustical design of a space involves the attenuation of unwanted and disturbing sounds

and the enhancement of desired sounds to the point at which they can be heard properly.

Exclusion of unwanted and undesirable noise is an important aspect of acoustics.

General requirement of acoustics are given below:

a. An adequate level of sound evenly distributed in a hall or room.

b. A suitable reverberation time (decay of sound) appropriate to the enclosed space and its

function.

c. Reduction of background and external noise.

d. Absence of echoes and other similar defects.

Acoustical materials are used to absorb or reflect sound from a surface. Some of the materials

are,

1. Sound reflecting materials – These are generally placed in the ceiling, back of the stage

and side walls of lecture halls. Materials such as wood, special plaster, concrete are sound

reflecting materials. The sound reflecting property of materials is expressed by their sound

reflection coefficients.


2. Sound absorbing materials – Absorption is expressed by the absorption coefficient. The

materials with loose structure such as carpets, glass, wool mats and perforated hardboards

(where the sound energy is lost in the holes) are called typical acoustic material.

3. Sound isolation materials and construction – Dense materials such as bricks do not allow

sound to pass through. There are many types of constructions such as solid brick walls, cavity

walls, double wall partitions with sound absorbing materials in between. The sound isolation

property of a material is expressed by the reduction of the noise in dB (decibels).

Air requirements

Ventilation is the process by which fresh air moved around the building. Good ventilation is

essential for the comfort and safety of building occupants, and in many cases subject to a

legal minimum requirement.

Requirement of space and air required

Space, m3 Air, m

3

Adult 8.5 20 – 30

Child 5.67 20 - 30

Main function of ventilation

1. To maintain the quantity of air inside the building at certain level.

2. To provide thermal environment which will aspect in maintain the heat balance of the

body.

3. To cool the structure of the building when the inside temperature is above outdoor.

4. To remove toxic gases, body odors, bacteria, smoke etc. from air inside the room.

5. During winter workers in factory and industrial plants from excessive heat, dust, moisture

and supply fresh air for breathing.

Ventilation can be provided through a number of methods, the most energy efficient being a

natural ventilation strategy. This requires specific design features to be included within the

building to ensure that there is a source of fresh air and a path for a measured amount of stale

air to escape. The simplest form of natural ventilation is through open windows, or through

window trickle vents.

Where a natural ventilation strategy is not possible either due to increased air flow rates

required, or a demand for cooling, mechanical ventilation or a full air conditioned strategy is

required. This is much more energy intensive due to the nature of the equipment (e.g. Fans)

required to move air around the building. It is possible to mix a natural and mechanical


ventilation strategy to achieve 'mixed mode' striking a balance between energy performance

and comfort.

Higher densities of people, IT equipment and lighting contribute to heat gain which requires

ventilation to remove stale air, maintaining a measured level of fresh air supplied to a

building. In order to maintain a desired temperature heating and cooling systems have to

work harder with an ineffective ventilation system in place.

Fig: Some aspects of ventilation in a building

BUILDING BYE-LAWS

The mode of construction from one region to other region varies depending on the motive of

owners, availability of materials and labor, construction techniques and weather conditions. If

certain rules and regulations are not made, house owner may construct residential building as

per his whims and fancies ignoring certain basic features connected with amenities,

ventilation and privacy of the inmates and with no regard for the privacy, safety and security

of neighbours and public at large at times even exceeding the far limits of decorum, deceny

and dignity.

A dilapidated house, a slanting compound wall or an illuminated well or septic tank nearer to

the neighbourhood may prove dangerous and detrimental to inmates, nieghbours and any roas

user.

An inundated road should never be used for traffic as nobody knows where the pavement lies

as it cannot be seen through muddy turbid waters. Electric power supply is a must for every

house either through an overheaded or buried cable below ground level which runs along the


public road and which is influenced by the alignment of the road. Same is the case with

telephone and TV cable connections.

Hence, rules and regulations which largely regulate the building activity should be

formulated to get disciplined growth of buildings and the better planned development of town

and cities. Minimum provisions designed from National Building code framed by Town

Planning authorities, Urban development authorities and Muncipalities, to protect the safety

of the public with regarding to the structural sufficiency, fire hazards and health aspects are

called Building Bye-Laws.

The building byelaws are defined as the standards & specifications designed to grant

minimum safeguards to the workers during construction, to the health & comfort of the users

and to provide enough safety to the public in general. The regulation set out the basic

requirements to be observed in the design and construction of buildings. They are applied to

new building and also to extensions, material alterations, and certain changes of use of

existing buildings. A building byelaw is a local law framed by a subordinate authority. It

channelizes to achieve the concepts & policies outlined in the Master plans of the city, in

order to give a particular architectural character to the city.

National Building Code has been published 1970 by Bureau of Indian Standards to maintain

uniform building regulations throughout the country for the guidance of Government

departments, Muncipal bodies, Urban development authorities and other construction

agencies. This National Building Code has been revised in 1983 after giving weightage to a

number of comments and useful suggestions for modification and after incorporating the

revised B.I.S. codes.

The National Building Code is a single document in which the information of bureau of

Indian Standards is presented in a systematic, cogent, coherent and continuous form. These

provisions will serve as a model for adoption by PWD’s and other government construction

departments, local bodies and private construction agencies. Existing PWD codes, municipal

bye-laws and other regulatory media could either be replaced or suitably modified to cater the

local requirements in accordance with the provisions of the code.

Objectives of building bye-laws:

The building bye-laws and regulations should be enforced by proper authority to achieve the

following objectives:

1. Building bye-laws allow disciplined and systematic growth of buildings and towns and

prevent haphazard development.


2. Building bye-laws protect safety of public against fire, noise, health hazards and

structural failure.

3. They provide proper utilization of space. Hence, maximum efficiency in planning can

be derived from these bye-laws.

4. Building bye-laws give guidelines to the architect or an engineer in effective planning

and useful pre-planning the building activities.

5. They provide health, safety and comfort to the people who live in buildings.

6. Due to these bye-laws, each building will have proper approaches, light, air and

ventilation which are essential for health, safety and comfort.

Following bye-laws and regulations cover all aspects of different types of buildings:

1. Line of building frontage and minimum plot sizes.

2. Open spaces around residential building.

3. Minimum standard dimensions of building elements.

4. Provisions for lighting and ventilation.

5. Provisions for safety from fire and explosions.

6. Provisions for means of access.

7. Provisions for drainage and sanitation.

8. Provisions for safety of works against hazards or accidents.

9. Requirements for off-street parking spaces.

10. Requirements for greenbelt and landscaping.

11. Special requirements for low income housing.

12. Sizes of structural elements.

RAIN WATER HARVESTING CONCEPT

In urban areas, the construction of houses, footpaths and roads has left little exposed earth for

water to soak in. In parts of the rural areas in India, floodwater quickly flows to the rivers,

which then dry up soon after the rain stops. If this water can be held back, it can seep into the

ground and recharge the groundwater supply. Rain water harvesting essentially means

collecting rainwater on the roofs of buildings and storing it underground for later use.

Town planners and civic authorities in many cities in India are introducing bylaws making

rainwater harvesting compulsory in all new structures. No water or sewage connection would

be given if a new building did not have provisions for rainwater harvesting. Realizing the

importance of recharging groundwater, the CGWB (Central Ground Water Board) is taking

steps to encourage rainwater harvesting in the capital and elsewhere. A number of


government buildings have been asked to go in for rainwater harvesting in Delhi and other

cities in India.

The amount of rainfall available varies from region to region. Each area has to develop its

own method and system to conserve, store and use it to suit its requirements and local

conditions. There are several methods by which rainwater can be stored, used and conserved.

Each system depends on the amount of precipitation, the period in which the rainfall occurs

in a year and the physical infrastructure for example, space available to store the water, etc.

There are several techniques available for catching and storing the rain-water. Most of the

techniques are applicable for large open areas, farms, sloping grounds etc, with a low

population base. Two major systems that are ideal for urban and semi-urban developed areas

are:

a) Artificial ground water recharge, and

b) Roof top rain-water harvesting.

Artificial ground water recharge

With increase in the impermeable surfaces in modem built up areas, a large quantity of water

normally percolating into the ground runs off to the natural drains and into the rivers causing

increased runoff and flooding of downstream areas as it also deprives the original catchment

area of the natural percolation that would have recharged the area in the normal course if the

ground was in its natural condition for example a farm, open ground, forest, etc. It is

therefore essential to catch the runoff and use it for augmentation of ground water reservoir

by modifying the natural movement of surface water by recharging it by artificial means for

example, construction of recharge structures.

Some of the artificial groundwater recharge methods are,

Absorption pit method.

Absorption well method.

Well cum bore method.

Recharge trench cum injection well.

The main objectives achieved may be:

a. Enhancement of sustainable yield in areas where there is over development and

depletion of the aquifers.

b. Conservation and storage of excess surface water in the aquifers.

c. Improve the quality of the existing ground water through dilution.


d. Remove bacteriological and suspended impurities during the surface water transition

within the sub-soil.

e. Maintain the natural balance of the ground water and its usage as the rain-water is a

renewable supply source. A well managed and controlled tapping of the aquifers will

provide constant, dependable and safe water supply.

In planning and designing the ground water recharge structures following should be taken

into consideration:

a) Annual rainfall (for estimating approx rainwater recharge per year).

b) Peak intensity and duration of each storm.

c) Type of soil and sub-soil conditions and their permeability factor.

d) Ground slopes and runoff which cannot be caught.

e) Location of recharge structures and its overflow outfall.

f) Rainwater measuring devices for finding the flow of water in the system.

Roof top rain-water harvesting

In areas having rainfall over a large period in a year for example, in hilly areas and coastal

regions, constant and regular rainfall can be usefully harvested and stored in suitable water

tanks. Water is collected through roof gutters and down take pipes. Provision should be made

to divert the first rainfall after a dry spell so that any dust, soot, leaves etc, are drained away

before the water is collected into the water tank. The capacity of the water tank should be

enough for storing water required for consumption between two dry spells. The water tank

shall be located in a well protected area and should not be exposed to any hazards of water

contamination from any other sources. The water shall be chlorinated using chlorine tablets

or solution to maintain residual chlorine of approximately 1 mg/1. The tank must have an

overflow leading to a natural water courses or to any additional tanks.

Some of the rainwater harvesting methods are,

Percolation pit method.

Bore well with settlement tank.

Open well method with filter bed sump.

Percolation pit with bore method.

In urban areas with the rainfall is limited during the monsoon period (usually from 15-90

days) roof top rain-water cannot be stored and used as mentioned above and is best used for

recharging the ground water. For individual properties and plots the roof top rainwater should


be diverted to existing open or abandoned tubewells. In a well planned building complex the

system should be laid out so that the runoff is discharged in bore-wells as per designs

specified by the Central Ground Water Board of the Government of India.

Fig: Typical rainwater harvesting facility for a building with two different methods

Rain water harvesting technique shall be adopted with due care taking following precautions:

a) No sewage or waste water should be admitted into the system.

b) No waste water from areas likely to have oil, grease or other pollutants should be

connected to the system.

c) Each structure/well shall have an inlet chamber with a silt trap to prevent any silt from

finding its way into the sub-soil water.

d) The wells should be terminated at least 5 m above the natural static sub-soil water at its

highest level so that the incoming flow passes through the natural ground condition and

prevents contamination hazards.

e) No recharge structure or a well shall be used for drawing water for any purpose.

CASE STUDY

In Bangalore the demand supply gap is met by groundwater exploitation. It is estimated that

40 per cent of the population is dependent on groundwater. Bangalore receives 970 mm

rainfall annually. Due to the availability of rainwater throughout the year, water is basically

stored in these rainwater harvesting systems and used for non-potable purposes. Water from

the rooftops is led into storage structures. This practice of storing rainwater is very common

in Bangalore for sustainable water supply.


Case study 1: R.V. College of Engineering faced a severe water shortage owing to pressure

on the aquifer system on campus. Due to this there was a substantial dip in the level of the

water table. This also led to the potential threat of contamination by sewage water. To

alleviate the situation, a plan for a rainwater harvesting unit was chalked out in consultation

with the college administration and Biome Environmental Trust. The installation of the unit

was completed within three months. The unit was designed to collect water from rooftops and

subsequently recharge the water table. The project has been operational since April 2010, and

has caused a substantial increase in the depth of the water table, making it possible to provide

potable water to the students' hostels on campus.

Case Study 2: Artificial Recharge in Jnanbharathi campus, Bangalore University

A scheme on artificial recharge to ground water is executed in Jnanabharathi campus,

Bangalore University which covered an area of about one sq km. The scheme on completion

helped in harnessing 0.043 MCM (43,000 m3) monsoon run off going as waste and improved

ground water levels and sustainability of abstraction structure in the area through artificial

recharge structures such as check dams and subsurface dyke. The salient features of the

recharge scheme given in Table below.

Catchment details Check Dam 1 Check Dam 2 Check Dam 3

Area (sq. m) 260000 340000 410000

Yield (cu. m.) 14860 19430 23430

Water available for recharge 75% of

yield (cu. m.) 11150 14570 17570

Artificial recharge structures were constructed to harness the natural surface water runoff

(43290 cu. m.) to recharge the aquifer system instead letting it into a drainage course. This

helped to maintain the productivity of the existing water supply of the borewells which

supply water to the University and Sports Authority of India campus. The scheme recharged

about 21645 cu. m. (50% of 43290 cu. m.) of potable water into the depleting aquifer system

in the area. Considering 20 years span of life for the structures, the annual investment with

10% rate of interest works out to Rs 80,740.00. The cost per thousand litre of water

harvesting works out to about Rs. 2.00. In addition to above, the possible intrusion of

polluted Vrishabhavati water to the aquifer in the area would be prevented.

green buildings

Documents