Section 22(2) in Punjab Urban Planning and Development Authority (Building) Rules, 1996
(2)Notwithstanding the obstruction by the projection and compound wall, habitable room shall have opening either directly or through an open verandah or courtyard, into an open space having a minimum width of three metres and the total aggregate openable area in the form of windows, ventilators, glazed doors or other apertures shall not be less than one-tenth of the floor area of the room.
