A guide for ADU construction in San Francisco, California

Yes, San Francisco allows ADUs on properties with existing or proposed single-family or multifamily dwellings. The city offers various programs—Local, State, and Hybrid—that determine the types and number of ADUs permitted based on your property's characteristics.

The permitting timeline varies depending on the complexity of the project and the program under which you're applying. Ministerial approvals under the State Program are typically faster, while Local Program applications may require more extensive review.

Under the State Program, one ADU is allowed per multifamily building. The Local and Hybrid Programs may permit more, depending on the building type and existing units.

No, there is no minimum lot size requirement for constructing an ADU in San Francisco.

Yes, a building permit is required for all ADU projects. The type of permit and review process depends on the ADU program applicable to your property.

ADUs must be at least 150 square feet. The maximum size varies: detached ADUs can be up to 1,200 square feet, while attached ADUs are limited to 50% of the existing dwelling's floor area, not exceeding 1,200 square feet.

Yes, two-story ADUs are permitted, provided they comply with height restrictions, setback requirements, and other zoning regulations.

There is no specific limit on the number of bedrooms in an ADU. However, the total size of the ADU must comply with the maximum square footage allowed.

ADUs must generally maintain a minimum setback of 4 feet from the side and rear property lines. Front yard setbacks vary based on zoning and other factors.

An ADU can share utilities with the primary residence or have separate connections. Separate meters are optional and may be installed based on the homeowner's preference and utility company requirements.

Fire sprinklers are not required in an ADU if they are not required in the primary residence. However, if the primary dwelling has fire sprinklers, the ADU must also have them.

Yes, new construction ADUs are subject to California's Building Energy Efficiency Standards, which may require solar panels, especially for detached units. Compliance depends on the specific characteristics of the ADU.

Rental rates for ADUs vary based on location, size, and amenities. In San Francisco, ADUs can command monthly rents ranging from $2,000 to $4,000 or more, depending on the neighborhood and unit features.

Short-term rentals (less than 30 days) of ADUs are generally prohibited in San Francisco unless specific conditions are met. It's crucial to consult local ordinances and regulations before listing an ADU as a short-term rental.

Homeowners Associations (HOAs) cannot unreasonably restrict the construction of ADUs. However, they may impose reasonable standards related to design and aesthetics.

Adding an ADU will increase your property's assessed value, leading to higher property taxes. The increase is based on the value of the new construction, not the entire property.

An ADU can significantly increase your property's value, often by 20-30%, depending on the quality of construction and local market conditions. Additionally, rental income from the ADU can enhance the property's appeal to potential buyers.

The cost to build an ADU in San Francisco varies widely based on size, design, and materials. On average, construction costs range from $150,000 to $400,000 or more. Garage conversions tend to be less expensive than new constructions.