Building bye-laws consists of certain rules and regulation framed by a municipal or town planning or urban development board to control the development of area under its jurisdiction. The aim of framing the bye-laws is to ensure provision of reasonable minimum requirements and standards (based on current scientific and engineering knowledge, experience, techniques and modern methods of construction) in the planning, designing and construction activities of buildings in the zone. The bye-laws are framed paying due regard to the weather conditions, Local construction practice, availability of materials, labor and other similar factors.
Objectives of Bye-Laws
The building bye-laws are essential to achieve the following objectives:-
- Distance from Electric Lines
As per national building code, no verandah, balcony or the like shall be allowed to be erected or re-erected or any additions or alteration made to a building within the distance quoted below in accordance with the current Indian Electricity Rules between the building and any overhead electric supply line.
- Lines of Building Frontage
A line usually parallel to the plot boundaries or center line of a road, beyond which nothing can be constructed towards the plot boundaries. This line is normally known as setback or front building line. The front building line is laid down in each case by the local authority as per the recommendation of Master/Zonal plan. Building like cinemas, factories, business centers etc., where large number of vehicles are anticipated require increased set back. Such increased set back line is termed as control line. Normally the distance of building control line is taken as 1/2 times the distance line. The distance of building line and control line for building facing a National State Highway in an urban area is taken as 30 m and 45 m respectively from the center line of the highway. The corresponding distance for building facing major roads in urban area is taken as 15 m and 24 m respectively. As per National Building Code there should be minimum frontage of 6 m for any building or any street.
The advantages of such building lines are:
- It permits acquisition of land for future widening of the street.
- It prevents formation of blind corners at the intersection of the streets and ensures improved visibility for the user of the road.
- It reduces impacts of street dust and noise, smoke etc, produced by the vehicular traffic on the occupants of the building.
- The portion of set back land can be conveniently used for parking gardening etc.
- Open Space Within the Plot
Every building should have provision of open spaces, inside and around the building to cater to the requirement of natural light and ventilation of the rooms abutting such open spaces. In case of buildings abutting on streets in the front, rear or sides, the extent of open spaces provided should be sufficient to permit future widening of such streets.
- Built up Area Limitation
Built up area or covered area of a building on ground is equal to:-
Plot area – Area of open spaces around the building
The ratio of total covered area of all floors to the area of plot on which the building is to be constructed is known as floor area ratio or F.A.R.
Floor area ratio = Covered area of the floors/Plot area
The floor area ratio is also termed as floor space index or F.S.I. The maximum area which can be allowed to be built on a plot of land and the maximum height up to which construction can be carried out on a plot is governed by the F.A.R. prescribed for the site by the local authority. The various aspects that are considered in specifying the value of F.A.R. for a site are given below:
- Type of occupancy i.e, residential or non residential.
- Type of construction.
- Width of street fronting the proposed building and the traffic load.
- Locality where the building is proposed and the density of that area.
- Parking facilities.
- Water supply, drainage system and fire fighting facilities.
- Lighting and Ventilation of Rooms
All habitable room shall have for the admission of light and air one or more openings such as windows, glazed doors and ventilators of fan lights, opening directly to the external air or into an open verandah not more than 2.4 m in width. In case it is necessary to have light and ventilation to habitable rooms through an internal courtyard the minimum dimensions of such courtyard shall not be less than 3 m x 3 m for building up-to 10 m in height. For higher buildings the minimum dimensions of the internal courtyard shall be governed by provisions in National Broadcasting Company (N.B.C.).
- Parking Space
The parking spaces to be provided in a building shall be as per the recommendations contained in the Master Plan/Zonal Plans and the regulations of the local authority. For areas not covered by the Master Plan/Zonal Plan and for occupancies where specific provision are not made, the provision of parking space shall be made as given below:
- One car space per 92.93 sq m of covered area. This parking can be provided in the form of open parking or covered parking. Provision of area to be made for each car space in different location shall be as under: (a) Basement = 35 sq m. (b) Stilts = 30 sq m. (c) Open = 25 sq m.
- Par king space shall be provided with adequate vehicular access to a street and the area of drive, aisles and such other provisions required for adequate maneuvering of vehicle shall be inclusive of the parking space stipulated in these rules.
- In addition to the parking space provided for buildings of mercantile (commercial), industrial and storage type, one parking space of 3.5 x 7.5 m shall be provided for loading and unloading activities for each 1000 sq m of floor area.
- Parking space shall be paved and clearly marked for different types of vehicles.
- In case of parking spaces provided in basements, at least two ramps of adequate width and slope shall be provided, located preferably at opposite ends.
- Exit Requirements
The following exit requirements shall be as under:
- Every building meant for human occupancy shall be provided with exits sufficient to permit safe escape of occupants in case of fire or other emergency.
- All exits shall be free of obstructions.
- Exists shall be clearly visible and the routes to reach the exit shall be clearly marked and sign posted to guide the population of floor concerned.
- All exit ways shall be properly illuminated.
- Fire fighting equipment where provided along exits shall be suitably located and marked in such a way as not to obstruct the exit way.
- Alarm devices shall be installed to ensure prompt evacuation of the population concerned through the exits.
- All exits shall provide continuous means of egress to the exterior of a building or to an exterior open space leading to a street.
- From fire safety/protection considerations all staircases must be segregated from the lift lobby/remainder of the floor/basement of each level by erecting fire resisting wall/smoke check door of not less than 2 hours and 1 hour fire rating respectively.
- Fire Protection Requirements
Building shall be planned, and designed and constructed in such manner as to ensure that it incorporates built in fire protection (safety) provisions in accordance with part of National Building Code (N.B.C) pertaining to fire protection of buildings. For multi-storeyed buildings which are more than 15 m in height and for special buildings like assembly, institutional, industrial, storage and hazardous occupancies. Following aspects shall need special considerations in the design of the building.
- Access to fire engines/vehicles through clear motrable access way all around the building.
- Safe area for firemen to assemble and equip themselves for fire fighting operation.
- Compartmentation of floor space for limiting the spread of fire.
- Provision of required number of safe (from heat and smoke) escape routes like protected staircase etc., for safe excavation of occupants.
- All enclosed staircases entered through fire resisting automatically closing type doors.
- Provision of fire lift for speedy means of access for firemen for fire fighting/rescue operations.
- Pressurization of stairwell, lifts shafts and lift lobbies when situated in the core block of building.
- Services shafts to be sealed at each floor. Inspection doors for shafts to be fire resisting.
- Requisite fire protection (sprinklers etc) and ventilation for basements and sub-basements.
- Provision of public address system.
- Provision of curtailment of fire spread through air conditioning ducts, service shafts, elevator shafts.
- Provision of generator of adequate capacity as alternative source to supply of power to specified equipment, lift and areas of buildings (escape routes etc.) in emergency.
- Adequate water storage facilities.
- Provision of safe ventilation of smoke, gases, fumes and heat.
- The underground water fire tank should be approachable by the fire tenders.
- Water mains telephones lines, fire detection installation line and intercom line etc., should not be laid in the same duct with the electric cables.
- Long corridors to be provided with self closing fire/smoke check doors.
- Structural Safety Requirements
The structural design of various components of the building viz, foundation, masonry wall, plain concrete work, reinforced concrete work,pre-stressed concrete work,timber as well as structural steel work etc., shall be carried out in accordance with the relevant I.S. code of practice applicable to the respective component. The building shall be design to be strong enough to resist safely and effectively all types of load and other forces to which it can reasonably be expected to be subjected to during its life time. All materials and workmanship shall be of good quality and confirming to the relevant I.S. codes, standard specifications of local P.W.D. etc.
- Building Services
This could be broadly divided into following parts are as under:
a) Electric Installation, Air Conditioning and Heating, Installation of Lifts and Escalators: The planning and installation of these services shall be carried out in accordance with provision contained in Part VIII of National Building Code pertaining of such service.
b) Plumbing Services: Planning, designing, construction and installation of plumbing services which inertia include water supply and drainage for different types of buildings (residential and non-residential buildings) shall be carried in accordance with the provision contained in Part IX of National Building Code pertaining to plumbing services.