9.20.1 Adequacy and manner of provision

i) The minimum aggregate area of opening of habitable rooms and kitchens excluding doors shall be not less than 1/10th of the floor area of the room.

ii) No portion of a room shall be assumed to be lighted, if it is more than 7.5 m. away from the opening assumed for light and ventilation, provided additional depth of any room beyond 7.5 m. may be permitted subject to provision of proportionate increase in the area of opening.

iii) A staircase shall be deemed to be adequately lighted and ventilated, if it has one or more openings and area taken together admeasures not less than 1.0 sq.m. per landing on the external wall.

iv) An opening with a minimum area of 1.0 Sq.m. in a kitchen, and 0.30 sq.m. with one dimension of 0.30 m. for any bathroom, water closet or store shall be treated as adequate.