ADU Regulations in San Francisco, California (2026)

Regulations at a glance

Local rules & notes

Seismic Retrofit Height Bonus: Buildings undergoing mandatory or voluntary seismic retrofitting may be raised up to three feet to create habitable ground floor space without a variance. Condo-Conversion Lottery Protection: Adding an ADU does not disqualify a building from entering the city's condo-conversion lottery. Eviction History Restriction: ADU applications will be denied if a tenant was evicted under specific codes within 5 or 10 years prior to the application.

For the official ordinance and latest updates, check your city or county planning department.

Frequently asked questions about ADU regulations in San Francisco

• What is the maximum ADU size in San Francisco, California?

  In San Francisco, the maximum ADU size is typically 1200 square feet, depending on whether the unit is attached or detached. California state law allows up to 1,200 sq ft for detached ADUs and 800 sq ft for attached in many jurisdictions; San Francisco may follow state defaults or have local limits. Verify with San Francisco planning for your specific lot.

• What are the setback requirements for ADUs in San Francisco?

  In San Francisco, typical setback requirements are 4 feet from the side property line and 4 feet from the rear. These may be reduced to 4 feet under California Government Code § 65852.2 where applicable. Check with San Francisco planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in San Francisco?

  In San Francisco, the maximum height for an ADU is generally 16 feet. State law often allows up to 16 feet for detached ADUs and up to 25 feet when within 4 feet of the property line in some cases. Confirm with San Francisco or county planning for your zone.

• Is ADU approval ministerial in San Francisco?

  In San Francisco, ADU approval is typically Ministerial (by-right) per Gov Code §65852.2. Ministerial (by-right) review means the city must approve qualifying applications without discretionary review, per California Gov Code § 65852.2. Your project must still meet objective standards; San Francisco planning can confirm the exact process.

• Are there parking requirements for ADUs in San Francisco?

  In San Francisco, parking for ADUs is generally false. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with San Francisco planning for your address.