In the low-density R zones, density is established as a single principal dwelling unit per lot. In those low-density residential zones that are limited to a single principal dwelling per lot, a single accessory apartment may be permitted per principal dwelling subject to conditions.
In the moderate-density RF zones, density is established as a maximum number of principal dwelling units per building, and in certain cases, through the number of principal dwelling units per minimum land area.
Occupancy of a principal dwelling unit is based on a household, unless otherwise permitted within a zone.
D.C. Mun. Regs. tit. 11, r. 11-B302