Accessory Dwelling Units (ADUs), also known as secondary or in-law units, were unanimously approved by the San Francisco Board of Supervisors Tuesday during the second and final round of votes. ADUs are now permitted in districts 3 and 8. The hope is that they will help to address the city’s housing shortage.
ADUs are designed to increase density without compromising a neighborhood’s character. The units, which are required to have a kitchen and bathroom, can be created in underutilized spaces such as garages or storage areas. Additions to the planning code specify that ADUs be “constructed within an existing building zoned for residential use or within an existing and authorized auxiliary structure on the same lot.” The code also allows ADUs to be built on the upper stories of new buildings, as existing buildings may have limitations. A property with 10 or fewer standard residential units can add one ADU, while buildings with more than 10 units can add two.
The city’s 2014 Housing Element encourages property owners to add these types of units to existing buildings to expand housing supply. Supervisors Scott Wiener, representing District 8, and Julie Christensen, representing District 3, proposed the legislation permitting the construction of ADUs in existing residential buildings within their respective districts. With planning approval, ADUs can be constructed in walkable neighborhoods that are adjacent to public transit and shopping — areas such as Noe Valley, Diamond Heights, Glen Park, Chinatown and North Beach.
The Planning Department will monitor ADUs for short-term rental use. There is trailing legislation related to ADUs that will be reviewed by the Planning Commission, including the ban on fractional ownership of ADUs, and prohibiting construction of ADUs on a property that has history of an Ellis Act Eviction in the last 10 years.