Residential Buildings

In addition to architectural, thermal comfort and fire-resistance requirements buildings will have to conform to development control rules. In this section the relevant rules (NBC, Part-111) are summarised. The word site (plot) is defined as a parcel (piece of land) enclosed by definite boundaries. Building line is defined as the line upto which the plinth of a building, adjoining  a street or an extension of a street or a street that may come up in future, may Iawfully  extend. Open space is defined as an area forming an integral part of the plot. left open to the sky. For other relevant definitions from NBC, refer Annexure - I. 

(A) Open Spaces within a Plot 

Front Open Space for every building fronting a street shall be a minimum of 1.5 m to a maximum of 6 m depending upon the width of the street, fronting the plot, (for exceptions refer to additional provisions in NBC). 

Rear Open Space for every residential building shall be on an average 3 m and at no place it shall measure less than 1.8 m. 

Side Open Spaces for detached buildings there shall be a minimum side open space of 3m on both the sides. For semi-detached buildings, there shall be a minimum side open 

space of 3 m on one side. 

For row-type buildings no side open space is required. All habitable rooms shall abut on the side open space or front and rear open spaces. These open spaces arc specified tor buildings of upto 10 m height. For buildings varying from 10 m to 24 m in height the side and rear open spaces may vary from 3 m to 8 m. and the front open space shall be at least 6 m. 

Area and Height Limitations 

The area and height limitations  of all buildings and types of construction are achieved by specifying the FAR, which takes into account the following factors : 

(i)  Occupancy class, 

(ii)  Type of construction, 

(iii) Width of the street fronting the building and its traffic load, 

(iv)  Locality where the building is proposed to be erected and the density of buildings, 

(v)  Parking facilities, 

(vi) Local fire-fighting facilities, and 

(vii) Water supply and drainage facilities. 

For residential building, for occupancies facing one public street of at least 9 m width the following FARs are specified : 

Type 1  Unlimited 

Type 2  2.0 

Type 3  1.4 

Type 4  1.0

(B) Requirements of Parts of Buildings 

Plinth : It shall not be less than 45 cm from the surrounding ground level to ensure adequate drainage. 

Habitable Rooms : The height of all rooms for human habitation shall not be less than 2.75 m measured from the surface of the floor to the bottom of the roof slab. The  of  shall not be less than 9.5 m2 where there is only one room of minimum width of 2.4 In. Where there are two rooms, one of these shall not be of less than 9.5 m2 and the other of not less than 7.5 m2 with a minimum width of 2.1 m. 

Kitchen : It shall have a height of 2.75 m and area shall not be less than 5 m2 with a minimum  width of 1.8 m. A kitchen, which is intended for use as a dining area also, shall have a floor area of not less than 7.5 m2 with a minimum width of 2.1 m (for other provisions refer to NBC, Part-111). 

Bathrooms and Water Closets : The height of such rooms shall not be less than 2 In and the size of the bathroom shall not be less than 1.5 m x 1.2 m or 1.8 m2. The-floor area of wafer closet shall be 1.1 m2 with a minimum width of 0.9 m. If bath and water closet are combined, its ma shall not be less than 2.8 m2 and the minimum width shall be 1.2 m. 

Lofts : They shall have minimum headroom of 2.2 m. Loft in a habitable room shall not cover more than 25 percent of the floor on which it is constructed and shall not interfere with  ventilation of the room. Maximum height of the loft shall be 1.5 m. On bath,  water-closets and corridors, the loft can cover 100 percent area. 

Stay Room : It shall have a minimum height of 2.2 m and the shall not be less than 3 m2. 

Garage : It shall have a minimum height of 2.4 m and the site shall not be less than 2.5 m x 5.0 m. 

Parapets : Parapets and hand-rails provided on the edges of roof terraces, balconies, verandas etc,. shall not be less than 1.05 m and not more than 1.20 m in height from the finished floor level. 

Boundary Wall : It shall have a maximum height of 1.5 m above the crown of the surface of the front street. Compound walls pf 2.4 m height may be permitted if the top 0.9 m is of open type construction. In the case of corner plots, the boundary wall shall be restricted to 0.75 m for a length of 10 m on the front and side of the intersections and the balance  height of 0.75 m may be made of open-type construction (railings etc.). 

Staircases : These shall have a minimum width of 1.0 m, minimum tread without nosing shall he 25 m. and the maximum rise shall be 19 cm. The minimum clear headroom in ally staircase shall he 2.2 m.