In this Chapter—

“clear height of a room “means the vertical distance from floor to underside of ceiling, or, if there is no ceiling, to the underside of rafters, beams, tie-beams or joists;

“court” means an unobstructed open space which abuts one or more of the external walls of a building, and which is located on the same stand as such building:

Provided that, where a court in any stand abuts—

a) A contiguous court on an abutting stand, and the local authority is satisfied that such contiguous court will not be detrimentally altered in size or shape during the life of any building served or to be served by the court first mentioned; or

b) An area on an abutting stand, which area is in terms of any law required to be kept free of any building or structure; or

c) A street;

Such court may, for the purposes of this Chapter, be deemed to include such contiguous court or such area or such street as the case may be;

“floor area” means the plan area of a room measured between internal-finished wall surfaces;

“habitable room” means any room designed for human occupation, but excluding bath-rooms, water-closets, stairways, passageways, lift-cars, photographic darkrooms, sculleries, domestic laundries, cold-rooms or garages used for parking alone;

“natural ventilation” means ventilation by natural means requiring no machinery;

“required ventilation-openings” means openings required to be provided by and complying with the provisions of this Chapter;

“ventilation-opening” means any opening in the wall of a room, whether permanently open or capable of being opened and shut, through which air may flow by natural means into or out of such room.