27. Exterior and interior open air spaces

(1) Every room intended for human habitation shall abut on an exterior or interior open space or verandah open to such exterior or interior

open space and such open space shall be maintained for the benefit of the building exclusively and shall be entirely within the owner’s own premises and shall be open to the sky and is barred from being subdivided, partitioned or legally bifurcated or transacted in any manner whatsoever, till such date when the structure itself is demolished and shall be kept free from any erection thereon other than those specially allowed in these rules. 

(2) In case a group of buildings are to be put up within any plot belonging to the same owner or by different owners of adjoining lands jointly the area of the land remaining after accounting for the mandatory front, rear and side yards from the boundary of the plot shall be considered as buildable area of the plot where the buildings may be constructed subject to the conditions regarding floor area ratio, coverage, access, light and ventilation,etc. for the whole plot. The distance in between the various blocks within this area shall be minimum 3 metres for buildings up to 10 metres in height.

(3) Every building up to 10 metres in height shall have a clear front yard of 3 metres depth: Provided that where this depth cannot be obtained laterally through out due to the peculiar shape of the plot, it shall suffice if the mean depth is not less than 3 metres with minimum depth at all points not less than 1.80 metres.

(4) Every building up to 10 metres in height shall have a minimum rear yard of 2 metres depth: Provided that where 2 metres depth cannot be maintained laterally throughout due to the peculiar shape of the plot, it shall suffice if the mean depth is not less than 2 metres with minimum depth at any point not less than 1 metre:

(5) Every building up to 10 metres in height shall have open air space of not less than 1.2 metres width on one of its sides other than the front and rear and not less than 1 metre on the other side: Provided that in the case of buildings upto 7 metres height, if 1.20 metres open space is available on one side, the open space on the other side can be reduced and can even abutthe boundary; and in case the building abuts the boundary or the open space is reduced to less than 75 metres the consent of the owner of the land on that side shall be obtained.

However no openings such as windows, doors 0.75 metre etc; shall be permitted if the open space against them is, less than 1 metre. But ventilator openings above a height of 2.10 metres, from the corresponding floor level may be permitted if the open space against them is not less than 75cm: Provided further that in the case of existing row houses the authority shall permit reconstruction, addition or construction of an upper floor for any of the dwelling units without any side set back on condition that the consent of the neighbouring owner concerned is obtained for the purpose.

(6) Any room intended for human habitation and not abutting on either the front, rear or side open spaces, shall abut on an interior open space whose width shall not be less than2.5 metres for buildings up to 10 metres height.Provided that in the case of buildings up to 7 metres height it shall be sufficient ifsuch interior open space has a minimum width of 1.5 metres.

 (7) The rainwater collected in a site shall not normally be allowed to flow in to the drain. It shall be retained in suitable pits of sufficient size taken within the site in order to allow the water to percolate in to the under ground. The pits shall be covered suitably, and arrangements shall be made to direct the water from all parts of the site in to the pit.

(8) For buildings above 10 metres in height, in addition to the minimum front, rear and side open spaces the minimum distance in between various blocks and the minimum width of interior open space required for height upto 10 metres, there shall be provided increase in such minimum open space at the rate of 0.5 metre for every 3 metres height or  part thereof exceeding 10 metres. Such additional set back corresponding to increase in height shall be provided for the whole building from ground level itself.

(9) No construction or hanging of any sort shall be permitted to project outside the boundaries of the site.

(10) Every open space provided, either interior or exterior shall be kept free from any erection thereon and shall be open to the sky and only cornice, roof or weather shade projections to a maximum width of 0.60metre shall be permitted. However the width of these projections may be increased as required if the depth of the open space is increased to that extent. Provided that the projections provided shall be so limited that the width of the remaining open space shall not be less than 0.50 metre: Provided further that where the mandatory open space has minimum 1.5 metres depth cornice, roof or weather shade up to 0.75 metre. shall be permitted to project and increase in the width of cornice, roof or weather shade shall be permitted corresponding to the increase in the mandatory open space: Provided further that open flight of steps or ramps meant, as access to upper or lower floors shall be permitted in the side or rear open spaces having a depth not less than 1.20 metres. Such stair, step or ramp shall have a minimum distance of 60cm. from the boundaries, for buildings up to 10 metres height from ground level; and for buildings above  10 metres height the open space shall be increased at the rate of 0.50 metres for every 3metres height or part thereof: Provided further that where the ground is below or above street level, either open steps, or ramp or bridge having width not exceeding the minimum access required under these rules or 3 metres whichever is higher shall be permitted from the street, to the building as means of access:Provided also that the underneath of such means of access shall not be enclosed;however pillars may be permitted for its support.

(11) The front, rear and side setbacks for constructions below the ground level(basement floor etc) shall be the same as that required for a 10 metre high building of the same occupancy group constructed above ground level.