PM-403.1 Habitable spaces: Every habitable space except kitchens shall have at least one openable window or skylight. The total openable area of the window in every room shall be equal to at least 45 percent of the minimum glazed area required in Section PM-402.1.3 and 402.1.4. A window which is disqualified by Section PM-402.1.1 or PM-402.1.2 shall also be disqualified as openable area.

Exception: Mechanical ventilation which complies with the mechanical code or which provides six air changes per hour to the space and exhausts to the outside shall be accepted in lieu of openable windows.

PM-403.2 Bathrooms and toilet rooms: Every bathroom and toilet room shall comply with the ventilation requirements for habitable spaces as required by Section PM-403.1, except that a window or skylight shall not be required in spaces equipped with a mechanical ventilation system which exhausts air from a toilet room or bathroom within a dwelling or rooming unit to the exterior without recirculation to any space, including the space from which such air is withdrawn.

PM-403.3 Laundry rooms: Every laundry room shall have a minimum openable area of two square feet (0.19 m²).

Exception: Mechanical ventilation which provides six air changes per hour to the room and exhausts to the outside shall be accepted in lieu of the openable area.

PM-403.4 Clothes dryers: Clothes dryer venting systems shall be independent of all other systems and shall be vented in accordance with the manufacturer’s instructions.