Any accessory use or accessory building shall be located on the same lot with the use or building to which it is accessory; provided, that required accessory parking space may be permitted on another lot where specifically permitted under other provisions of this title.
An accessory building shall be located only in a rear yard, except as follows:
No more than thirty percent (30%) of the area of a required rear yard on any lot shall be occupied by accessory buildings.
An accessory building in any zone district shall not exceed one (1) story or fifteen feet (15 ft.) in height, except as provided in § 2500.5.
In an R-1-A or R-1-B District only, an accessory private garage may have a second story used for sleeping or living quarters of domestic employees of the family occupying the main building.
A two (2) story accessory building allowed under § 2500.5 shall not exceed twenty feet (20 ft.) in height and shall not be located within the required rear yard. It shall also be set back from all side lot lines for a distance equal to the minimum width of a required side yard in the district in which it is located.
The height of an accessory building permitted by §§ 2500.4 or 2500.5 shall be measured from the finished grade at the middle of the side of the accessory building that faces the main building to the highest point of the roof of the building.
An accessory building or structure shall not be erected on any lot prior to the time of construction of the main building to which it is accessory.
An accessory building shall not obstruct light and ventilation required by other regulations.
D.C. Mun. Regs. tit. 11, r. 11-2500