(A) Every habitable room shall have a ventilation system adequate for the purpose for which the room is used. Natural ventilation shall be deemed to be adequate for a habitable room when the total area openable to the outside air (by means of windows, louvers, monitors or other direct openings excluding doors) is 5% of the floor area of the habitable room, except that when:
(1) Any portion of the room is more than 16 feet from a required opening, the aggregate clear area of openings shall be not less than 6%.
(2) A room has openable areas on two or more sides thereof, the total openable area shall be at least 4% of the total floor area of the room.
(3) The openable area faces a wall or other obstruction at a distance of less than ten feet, the effective area shall be computed at not more than 80% of the actual openable area.
(4) The openable area opens onto an enclosed porch, the enclosed porch shall have an openable area of at least three times the total required area of the openings onto the porch.
(B) A kitchen with a floor area of less than 70 square feet may be without either mechanical or natural ventilation if there is an opening of not less than 32 square feet between the kitchen and another room in the same family unit and if the room into which the kitchen opens has the ventilation requirements of the preceding paragraphs.
(C) (1) Every toilet room and bathroom shall have adequate ventilation which may be either an openable window with an openable area of 5% of the floor area, mechanical ventilation in compliance with the foregoing requirements of this section, or a gravity vent flue constructed with incombustible material leading to the roof of the building or a combination of any of these.
(2) The gravity vent shall be computed at an aggregate clear area of not less than 5% of the floor area of the room with a minimum area of at least 120 square inches.
(3) Gravity vents shall be provided with a weather cap, directional vane or rotary type ventilation on the roof.
(Ord. 885, passed 1-2-1974; Am. Ord. 1102, passed 7-15-1986) Penalty, see § 151.99