6.9 Interior & exterior chowk

(a) Interior chowk : Wherever habitable rooms or kitchen derive ventilation from inner chowk or interior open space, the minimum size of such interior open space shall not be less than 3.0 m. x 3.0 m. (1) Further such interior chowk shall have an area of not less than the square of one sixth of the height of the highest wall abutting the chowk considered from the lowest point of the chowk, at all levels.

(b) Exterior chowk : The minimum width of the exterior chowk for the purpose of light and ventilation shall not be less than 2.4 m. and the depth shall not exceed 2 times the width, for buildings up to 17.0 m. height and for height more than 17.0 m., the exterior open space shall not be less than H / 7 m. x H / 7 m. where H = Height of highest wall of the Chowk from ground level. If the width of the exterior chowk is less than 2.4 m., it shall be treated as a notch and shall not be considered for deriving ventilation.

(c) Where only water closet, bathroom, combined bathroom and water closet are abutting on the interior open space, the size of the interior open space shall be in line with the provision for ventilation shaft as given in Regulation No.9.20.2.

Provided that, for (a) and (b) above maximum distance shall be subject to 16.0 m. If the owner wishes to provide chowk size more than what is prescribed above, it shall be allowed.