ADULocal ADU Guide

Bay Area region / California

San Francisco ADU rules
& permit guide.

San Francisco has State and Local ADU programs. The right path depends on the existing building, the proposed ADU type and the work involved. SF Planning's June 2026 bulletin explains the State program separately for single-family and multifamily properties.

Editorial review 2026-09-07 · View sources

The local detail to check first

Before you choose a design

Do not apply a single-family size limit to a multifamily project. Confirm the program before using a dimensional standard.

Local requirements at a glance

Min/max ADU size

State detached ADU on a single-family lot: up to 850 sq ft for a studio or one bedroom; 1,000 sq ft for two or more bedrooms. Other ADU types have different standards.

Height

State detached ADU: up to 18 feet, plus 2 feet where needed to align the roof pitch with the primary home.

Setbacks

State detached ADU: 4-foot side and rear setbacks. A replacement in the same location and dimensions can qualify for an exception.

Parking

Confirm the applicable parking exemption with the city. HCD's current handbook explains the state exemptions and replacement-parking rules.

Process

Identify the property's zoning and existing legal units. Discuss the State and Local program paths with Planning. Use the requirements for your specific building and ADU type to prepare the permit application.

Your next three steps

  1. Identify the property's zoning and existing legal units.
  2. Discuss the State and Local program paths with Planning.
  3. Use the requirements for your specific building and ADU type to prepare the permit application.

2026 state-law context

ADUs and JADUs have different occupancy rules

California generally prohibits local owner-occupancy requirements for ADUs. A narrow exception applies to certain separately sold affordable ADUs. For JADUs, owner occupancy generally applies when the bathroom is shared with the main home; separate-bathroom JADUs are treated differently under 2026 law. Check the HCD handbook and your project's permit conditions.

Older local summaries may not reflect the latest state changes. Read HCD’s March 2026 handbook, pages 32–33.

Questions for your first planning conversation

  • Which approval path applies to my building and ADU type?
  • Do easements, trees, slope, access or fire conditions affect placement?
  • Which utility upgrades and agency reviews should be included in my budget?
  • Are preapproved plans available, and what site work still needs review?