D.C. Mun. Regs. tit. 12, r. 12-G402
Strike Section 402.1 of the International Property Maintenance Code in its entirety and insert new Section 402.1 in its place in the Property Maintenance Code to read as follows:
General. Every space intended for human occupancy shall be provided with natural light by means of exterior glazed openings in accordance with Section 1205.2 of the Building Code or shall be provided with artificial light in accordance with Section 1205.3 of the Building Code.
Exception: Artificial light shall not be used to meet the lighting requirements for bedrooms, living rooms and sleeping units.
Natural light. Where natural light is required, the minimum net glazed area shall be not less than 8 percent of the floor area of the room or rooms served. At least 50 percent of required glazing shall be clear glass; it is permissible for the remainder of the required glazing to be obscure glass, glass block or other approved translucent material.
Adjoining spaces. For the purpose of natural lighting, any room is permitted to be considered as a portion of an adjoining room where one-half of the area of the common wall is open and unobstructed and provides an opening of not less than one-tenth of the floor area of the interior room or 25 square feet (2.32 m2), whichever is greater.
Exception: Openings required for natural light shall be permitted to open into a sunroom with thermal isolation or a patio cover where the common wall provides a glazed area of not less than one-tenth of the floor area of the interior room or 20 square feet (1.86 m2), whichever is greater.
Exterior openings. Exterior openings required by Section 402.1 for natural light shall open directly onto a public way, yard or court, as set forth in Section 401.3.
Exceptions:
Abuts a public way, yard or court;
Has a ceiling height of not less than 7 feet (2134 mm); and
Has a longer side at least 65 percent open and unobstructed.
Strike Section 402.1.2 in the International Property Maintenance Code in its entirety and insert a new Section 402.1.2 into the Property Maintenance Code in its place to read as follows:
Artificial light. Artificial light shall be provided that is adequate to provide an average illumination of 10 footcandles (107 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level.
Strike Section 402.2 of the International Property Maintenance Code in its entirety and insert new Section 402.2 in the Property Maintenance Code in its place to read as follows:
Common space and stairways. Every common space and stairway in residential occupancies, other than in one family dwellings, shall be lighted at all times with a minimum of 15 footcandles (164 lux) at floor level. Means of egress serving more than two dwelling units, including exterior means of egress, shall be illuminated at all times the building space served by the means of egress is occupied with a minimum of 1 footcandle (11 lux) at floors, la ndings and treads.
Other spaces.
Insert new Section 402.3.1 into the Property Maintenance Code to read as follows:
Bathrooms. Each bathroom, toilet room or compartment, and other similar rooms shall be naturally or artificially lighted at least equivalent to the requirements of Section 402. Naturally lighted bathrooms, toilet rooms or compartments, and other similar rooms shall be provided with aggregate glazing area of not less than 3 square feet (0.3 m²).
D.C. Mun. Regs. tit. 12, r. 12-G402