Plinth Area And Plinth Regulation Of The Building Construction

Plinth Area:

The minimum area of buildings of different classes shall be governed by the following:

In an industrial plot, the plinth area should not exceed 60% of the site area.

In a market area, the plinth area should not exceed 75% of the area of site, provided sufficient off-street parking facilities for loading and unloading of vehicles are provided on the same plot as the building.

In residential plots, the covered areas should be as given in the table 1.

S. No	Area of plot	Maximum permissible covered area
1	Less than 200 sq.m	66.66 % of the plot area on the ground and first floor and nothing on the second floor, except a barsati (garret) not exceeding 25% of the ground floor.
2	201 to 500 sq.m	50% of the plot area or 133 sq.m whichever is more.
3	501 to 1000 sq.m	40% of the plot area or 250 sq.m whichever is more.
4	More than 1000 sq.m	33.33 % of the plot area or 400 sq.m whichever is more.

Plinth Regulation:

a) Main Building: No plinth or any part of a building or outhouse should be less than 30cm above the determined level of

i. the central part of the abutting street,

ii. the footpath of the abutting street,

iii. the height part of a service lane which determines the drainage of the premises,

iv. any portion of the ground within 3m distance of such a building, and

v. undulating or sloping land 1.2 m above the drainage or country water level.

in cases where adequate drainage of the premises is not assured, the plinth should be of a height approved by the authority.

b) Interior courtyards: Every courtyard should be raised atleast 15cm above the level of centre of the nearest street and should be satisfactorily drained. Common courtyards should have independent access.

c) Plinth of garages, stables and warehouses: the plinths of such constructions should not be less than 15cm above the level determined in portion (a) above for main building.

Height And Size Regulations Of Rooms In Building Construction

Height Regulation:

Habitable rooms: The minimum height from the surface of the floor to the ceiling or bottom of slab should be not les than 2.75m. For air-conditioned rooms, a height of not less than 2.4 m measured from the top of the floor to the lowest point of the air-conditioning duct or the false ceiling should be provided.

Bathrooms, water closets and stores: The height of all such rooms measured from the floor in the ceiling should not be less than 2.4m. In the case of a passage under the landing, the minimum headway may be kept as 2.2m.

Kitchen: The height of the kitchen measured from the floor to the lowest point in the ceiling should not be less than 2.75m except for the portion to accommodate floor trap of the floor.

Ledge: It shall have a minimum head room of 2.2m.

Size Of Rooms:

Habitable rooms: The area of habitable rooms should not be less than 9.5 sq.m where there is only one room. Where there are two rooms, one of these should not be less than 9.5 sq.m and other be not less than 7.5 sq.m with a minimum width of 2.4m.

Kitchen: Minimum floor area required is not less than 5.5 sq.m. It should not be less than 1.8min width at any part. With a separate storeroom, the area may be reduced to 4.5 sq.m. A kitchen cum dining room should have a floor area not less than 9.5 sq.m with a minimum width of 2.4m. Each kitchen should be provided with a flue.

Bathrooms and water closets: The size of bathroom should not be less than 1.5m x 1.2m or 1.8 sq.m. If it is combined with water closet, its floor area should not be less than 2.8 sq.m. the minimum floor area of a water closet should be 1.1 sqm.

Ledge: A ledge in a habitable room shall not cover more than 25% of the floor area of the floor on which it is constructed and should not interfere with the ventilation of the room under any circumstances.

The minimum size of a mezzanine floor, if it is used as a living room, should not be less than 9.5 sq.m.

Lighting And Ventilation Requirements Of Rooms In Building Construction

Lighting And Ventilation Requirements Of Rooms In Building Construction

a) Rooms: Every habitable room which should have for the admission of air and light, one or more apertures such as windows and fanlights, opening directly to the external air or into an open verandah and of an aggregate area, inclusive of frames, of not les than

i. One-tenth of the floor area excluding doors for dry hot climate.

ii. One-sixth of the floor area excluding doors for wet/hot climate.

No portion of a room should be assumed as lighted if is more than 7.5m away from the door or window which is taken for calculation as ventilating that portion.

Cross-ventilation by means of windows and ventilators or both shall be effected in at least living room of tenement either by means of windows in opposite walls or if this is not possible or advisable, then atleast in the adjoining walls.

b) Bathrooms and water closets: The rooms should be provided with natural light and permanent ventilation by one of the following means:

i. Windows having an area of not less than 10% of the floor area and located in an exterior wall facing a street alley, yard or an air shaft whose dimensions in the direction perpendicular to the window is not less than one-third the height of the building on which the window is located, subject to a minimum limit of 1m and maximum 6m.

ii. Skylights, the construction of which shall provide light and ventilation required in (i) above.

iii. Ventilation ducts: Provided such ducts have 130 square cm of area for each square meter of area with a minimum total area of 300 square cm and least dimension of 9cm.

c) Stores, backrooms: These will have atleast half the ventilation required for living room.

d) Basement and floors: Basements and rooms located therein except room shall be lighten and ventilated by windows in exterior walls having a ventilating area of not less than 2.5% of the floor area.

e) Kitchen shall be ventilated according to standards prescribed for habitable rooms near the ceiling as far as possible.

f) Stairways: every staircase should be lighted and ventilated from an open air space of not less than 3m depth measured horizontally in case of ground and one upper floor structure, 4.5 m in case of ground and two upper and in higher structure than this, the open air space shall not be less than 6m, provided that the lighting area shall not be less than 1 sq.m per floor height. Every staircase shall be ventilated properly.

Requirements Of Staircase And Bathrooms In Building Constructions

Requirements of staircase and bathrooms other than lighting and ventilation are given here.

Other Requirements Of Staircase:

The minimum clear width of staircase in case of residential buildings shall not be less than 1m. In case of a public building, a staircase not less than 1.2m in width should be provided for 600 persons or thereof, expected to use the building and the farthest corner of the building shall not be more than 30m distant from the staircase. The maximum riser and minimum width of tread of staircase should be as given in the table 2.

Type of Building	Maximum riser	Minimum tread width
Public buildings	15 cm	30 cm
Domestic buildings	19 cm	25 cm

Other Requirements In The Construction Of Bathrooms And Water Closets:

1. Every water closets or bathroom should
2. Be so situated that at least one of its walls shall be open to external air.
3. Not be directly over or under any room other than another latrine, washing place, bath or terrace, unless it has a water tight floor.
4. Have the platform or seat either plastered with cement or be made of some water tight non-absorbent materials,
5. Be enclosed by walls or partitions of bricks. Surface of every such wall or partitions should be finished with a smooth impervious material, such as cement plaster, 1.3cm thick of glass glazed tiles or polished marbles or any suitable material to a height of not less than 1m above the floor of such a room.
6. Be provided with an impervious floor covering sloping towards the drain and not towards varnishes or any other room.
7. Have a floor level of such a height as to ensure suitable grade towards the sewage drain.

Building Construction Regulations For Projections From Buildings

Projections from Buildings

No projections of any sort what so ever extending more than 23 cm below a height of 4.3m, such as projection on the level of chajja, cornice, water spouts, drains, pipes, advertisement boards and the like shall project over the land of the road or over any drain of the vertical part of the rain water spouts projecting at the road level or the water pipe may be permitted in accordance with the drainage plan.

a) Sunshade over windows and ventilators: Projections of sunshades over windows or ventilators when permitted by the authority shall fulfill the following conditions:

i. Notwithstanding anything contained in these bye-laws, no projection of any sort shall be permitted over the land and the road or over any drain or over any portion outside the boundaries of the site below a height of 2.8 m from the road level.

ii. Sunshades provided above a height of 2.8 m from the ground level shall be permitted to project upto a maximum width of 60 cm if the road over which they project exceeds 9m in width.

iii. No projection of any sort whatever shall be permitted on roads less than 9m in width or on roads having no footpaths.

b) Porticos in existing developed areas: Porticos may be allowed in such roads as can leave a minimum clear space of 18m between kerbs or if a stipulation has been made for such construction in the lease deed or in such cases where its construction would completely fall in a gap in the existing arcade, provided that these shall be constructed as follows:

i. It shall not be less than 3m wide and is either cantilevered or supported on thin steel or RCC pillars.

ii. Nothing shall be allowed to be constructed on the portion which shall be used as an open terrace.

iii. Nothing shall be allowed to project beyond the line of arcades.

iv. The space under the portion shall be paved and channeled according to the directions of the authority.

Factories And Industrial Buildings Construction Regulations

Notwithstanding any provisions provided, in any one of these bye-laws, every factory building or part thereof shall comply with the following additional regulations:

a) Site: The location of every factory site shall be governed by the provisions of the development plan. For cities having no development plans, the factory site shall have to be approved by the authority.

b) Means of escape in case of fire: In the case of factories constructed or converted to use as a factory after the date of enforcement of the these regulations the following additional requirements shall apply:

i. At least two of the stairways provided should be of the fire resisting materials.

ii. No stairway shall be less than 1.2m in width.

iii. All the stairs shall have an unobstructed head room of at least 2.1 m measured vertically above the tread in line with the face of the riser.

iv. In straight treads, the run of the treads shall not be less than 25 cm wide and the rise shall not be more than 18cm high. The width of the tread including nosing shall not be less than 27 cm.

v. No part of a factory building shall be farther than 15 m from any one of the fire escapes.

vi. Every staircase provided above shall be lighted and ventilated from an air space of not less than 3m depth, measured horizontally in case of ground and one upper floor structure, 4.5m in case of ground and two upper and higher structures than this shall not have an air space of less than 6m, provided that the lighting and ventilating area shall not be less than 1 sq.m per floor height.

vii. Every person who undertakes construction of a factory building shall construct lobby, landing corridor or passage included in such work that it shall in no part be less than 1.2 m in width free from encroachment of any kind and its floor shall be of fire-resisting materials and supported by fire-resisting materials.

viii. Every hoist-way or lift-way inside a factory building shall be completely enclosed with fire-resisting materials and means of access to that hoist or lift, shall be fitted with doors of fire-resisting materials, provided that such hoist-way or lift-way shall be enclosed only at the top by some material easily broken by fire or be provided a vent at the top. Escape arrangements should be fully in terms of section 38(7) of the Indian Factories Act,1948.

Abutment of over crowding:

These should be provided at all times for each person employed in any room of the factory at least 3.4 sq.m f the floor space exclusively of that occupied by the machinery and a breathing space of atleast 14 cubic meter.

Height of work Rooms

The internal heights of a work room shall not be less than 4.5 m measured from the floor level to the lowest point in the ceiling.

Percentage of Coverage:

Not more than three-fifths area of the site may be covered subjected to the mandatory open spaces specified as above:

Front area – 7.5 m

Side yard – 3.0 m

Rear yard – 7.5 m

Miscellaneous

Unfinished buildings: No building should be left with unfinished portions including projecting reinforcing bars, which in the opinion of the authority are unsightly unless within the permission prescribing conditions with respect to the structure and the period for which such permissions remain valid.

Clearing of site: As soon as any building is completed, all rubbish, refuse or debris of any description shall be removed by the owner from the site or sites on which building operations have been carried out or from any adjoining land which may have been used for deposition of debris.