D.C. Mun. Regs. tit. 12, r. 12-G401
Strike Section 401.3 in the International Property Maintenance Code in its entirety and insert new Section 401.3 into the Property Maintenance Code in its place to read as follows:
Window obstruction where natural light or natural ventilation is required. Exterior glazed openings shall open directly onto a public way or onto a yard or court in accordance with the provisions in effect when the building was approved for occupancy. Wherever walls or other portions of a structure face a window of any room and such obstructions are located less than 3 feet (914 mm) from the window and extend to a level above the sill of the window, such window shall not be deemed to face directly to the outdoors nor to a court and shall not be included as contributing to the required minimum total window area for the room. A reasonable number of trees or shrubs shall not violate this section.
Insert new Section 401.4 into the Property Maintenance Code to read as follows:
Habitable spaces.Habitable spaces are permitted below grade plane, provided they meet the requirements of this code.
D.C. Mun. Regs. tit. 12, r. 12-G401