Laws to legalize in-law units, construct new units in Castro approved by supervisors

Tens of thousands of existing in-law units could become legal in San Francisco and new secondary units could be constructed in the Castro neighborhood with the approval of two laws by supervisors Tuesday.

Facing mounting pressure to address soaring rents and evictions, the Board of Supervisors has turned its attention to in-law units, which are a portion of The City’s overall housing stock that has long provided tenants with the option of less expensive rents.


The board has unanimously approved legislation by Supervisor Scott Wiener that would allow the construction of new in-law units in the Castro. It is being eyed as a pilot program that could be expanded to other neighborhoods.

“Very little new housing is being built in the neighborhood,” Wiener said. “There are many residents in the Castro who are concerned about the extreme costs of housing in the neighborhood and whether they will be priced out of the neighborhood, and they wonder where they will go.”

The legislation would allow the construction of one secondary unit of up to 750 square feet in buildings of up to 10 units and two in-law units in buildings that have more than 10 units.

The new living spaces must only be created within the existing building footprint and not be currently used as residences. Spaces such as garages, basements or large ground-floor storage are ideal.

Up to 400 in-law units could be created in the Castro area under the legislation. But it is unclear how many building owners will actually take advantage of it. Units being added to rent-controlled buildings, those built before 1979, would fall under the rent control law.

The board also voted to give final approval to legislation introduced by board President David Chiu that creates a pathway for building owners to legalize the estimated 30,000 to 50,000 existing secondary housing spaces.