DC now allows accessory apartments to be built in residential zones.


DC Zoning commission has finally adopted a new zoning code. One of the most notable changes was a provision that allowed for the by-right development of Accessory Apartments (also commonly known as Accessory Dwelling Units, or ADUs) in certain residential zones in the city.

What is an accessory apartment?

An accessory apartment is a secondary dwelling unit established in conjunction with and clearly subordinate to a primary dwelling unit. It could be a part of the same structure as the primary dwelling unit or a detached dwelling unit on the same lot. These units might be an addition to a garage, an entirely new structure, or a basement or attic apartment in the existing single-family house

DC’s new zoning code allows the development of an accessory apartment as a matter-of-right in almost all residential (R) zones (zones R-19 and R-20 are the exception). This means that homeowners in the R zones can construct an accessory apartment without needing special permission to do so.

Here are some Examples: