Washington, DC Building Setbacks & Zoning: Setback Rules (2026)

2 requires a residential building's front setback to fall "within the range of existing front setbacks of all residential buildings on the same side of the street in the block where the building is proposed," so the rule is contextual and block-specific. Section 207's Table D fixes the minimum rear yard by zone: 25 feet in R-1, and 20 feet in each of R-2 and R-3. That rear yard can be waived entirely where the rear lot line abuts a public open space, recreation area, or reservation, and older buildings that predate May 12, 1958 keep limited rights to extend into the area that was already built out at that time.

Section 208 governs side yards: detached buildings need two side yards of at least 8 feet each; in the R-2 zone, semi-detached buildings need one 8-foot side yard; in R-3, semi-detached buildings need only one 5-foot side yard, and row buildings, the dominant housing type the zone is built around, need no side yard at all. A side yard can also be reduced or dropped on a corner lot's street-side yard or where a lot abuts public open space. Existing side yards that already meet the code cannot be shrunk below a conforming width by a later addition.

As with lot occupancy, none of these yard minimums can be waived by the applicant; the Department of Buildings' Zoning Administrator checks compliance at building-permit review under Subtitle A Section 301 before construction can proceed.