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D.C. Municipal Regulations (Last Updated: September 13, 2017) |
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Title 14. HOUSING |
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Chapter 14-5. HOUSING CODE: HEATING, LIGHTING, AND VENTILATION |
Section 14-506. VENTILATION OF HABITABLE ROOMS
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506.1Each habitable room shall have either natural or mechanical ventilation at least equal to the requirements of this section.
506.2Natural ventilation shall be provided by an opening directly to the outside, the area of which is at least equal to five percent (5%) of the floor area of the room served, except as otherwise provided in this section.
506.3Rooms opening on enclosed porches and meeting the ventilation requirements of Article 501-01-e of the 1941 Building Code, as amended, and rooms ventilated through sunporches and meeting the ventilation requirements of § 3-515 of the 1961 Building Code, as amended, shall be deemed to have adequate natural ventilation.
506.4At least fifty percent (50%) of the required ventilation shall be furnished by an openable window, louvres located in the upper fifty percent (50%) of the room, side light, transom, glazed door, or door of the horizontally divided (dutch) or vertically divided (french) type.
506.5For buildings erected, altered, or converted under permits issued prior to July 1, 1961, mechanical ventilation where used shall provide habitable rooms, other than kitchens, with at least three (3) air changes per hour.
506.6Kitchens shall be provided with at least four (4) air changes per hour.
506.7Openable area directly to the outside at least equal to three percent (3%) of the floor area of the habitable space served shall be available for use in case of temporary failure of mechanical ventilation, except as provided in § 506.8.
506.8Interior kitchens which are not daylighted as required by § 502 may be artificially lighted and mechanically ventilated if they comply with the following:
(a)Total floor area shall not exceed one hundred square feet (100 ft.2);
(b)Unobstructed floor space (after the installation of kitchen cabinets and equipment including space reserved for the installation of stove and refrigerator) shall not exceed fifty square feet (50 ft.2);
(c)Mechanical ventilation shall be centrally controlled and operated and shall provide a minimum of eight (8) changes of air per hour through an independent duct system; and
(d)The interior kitchen is not to be counted as a habitable room.
506.9Not more than seventy-five percent (75%) of the air supplied by mechanical ventilation shall be recirculated air.
506.10The recirculation of air from kitchens, bathrooms, furnace rooms, laundry rooms, and garages is prohibited.
506.11No air supplied to habitable rooms shall be drawn from a plenum or system fed with air returned from habitable rooms occupied by other families, common space, or commercial or industrial establishments.
506.12For buildings erected, altered, or converted under permits issued after June 30, 1961, the requirements for mechanical ventilation shall be in accordance with the applicable provisions of sections 3-527 through 3-533, inclusive, of the 1961 D.C. Building Code, as amended.