507.1 Each bathroom shall be naturally or mechanically ventilated, at least equivalent to the requirements of this section.

507.2 Natural ventilation shall be provided by openings, other than a door, directly to the outside, the openable area of which is at least equal to five percent (5%) of the floor area of the room served.

507.3 No opening for ventilation of a bathroom shall contain less than two square feet (2 ft.²).

507.4 If mechanical ventilation is used, it shall provide for each bathroom with a single water closet outside air in a minimum quantity of one and one half cubic feet per minute per square foot of floor area (1½ ft.³/min./ft.²), with no recirculation permitted.

507.5 A bathroom having more than one water closet shall be provided with a minimum outside air quantity of two and one half cubic feet per minute per square foot of floor area (2½ ft.³/min./ft.²), with no recirculation permitted.

507.6 A mechanically ventilated bathroom shall not serve or open into any area that opens on, or is served by, a bathroom that is not similarly ventilated.

SOURCE: The Housing Regulations of the District of Columbia, 5G DCRR §§ 2309, 2309.6, Commissioners' Order 55-1503 (August 11, 1955); as amended by Commissioners' Order 66-314 (March 8, 1966).