Exterior entrance of an Accessory Dwelling Unit
Credit: San Francisco Planning

Accessory Dwelling Units

If you are applying for a permit to add an Accessory Dwelling Unit (ADU), start your application online.

We are currently processing ADU applications submitted the week of April 12, 2021.

Last updated: April 16, 2021

Accessory Dwelling Units (ADUs), also called secondary units, in-law units, or cottages, are units added to existing and new residential buildings. In 2016, San Francisco's Accessory Dwelling Unit Program became available Citywide in zoning districts that permit residential use.

Adding an ADU to your property can provide several benefits, such as providing housing for family members, simplifying your lifestyle, and increased financial flexibility. For more information on the benefits of ADUs, please see our video, "Are ADUs Right For You?"

There are two ADU Programs: State-Mandated and Local; and two categories under State law: Streamlined and Ministerial. These are discussed further under each corresponding tab.

Mayoral Directives

On August 31, 2018, Mayor London N. Breed issued Executive Directive 18-01 to accelerate the approval of Accessory Dwelling Units (ADUs), commonly known as in-law units, and to clear the backlog of pending applications. On September 27, 2017, Mayor Edwin M. Lee issued Executive Directive 17-02, charging all City Departments to work collaboratively toward faster approvals for housing development projects at both the entitlement and post-entitlement permitting stage. Learn more about these directives.

State-Mandated Program

Also known as No-Waiver ADUs, this program applies to single- and multi-family buildings and offers several options for creating ADUs. State law may prevent the City from subjecting some ADUs to the rent stabilization provisions (rent control) of the San Francisco Rent Ordinance. See the State Law tab for details.

ADUs in the State Program are subject to the following:

  • 60-day review timeframe
  • No subjective design review
  • Not subject to review under the California Environmental Quality Act (CEQA)
  • Not subject to Planning Code Section 311 neighborhood notification requirements
  • No discretionary review opportunity
  • Shortened appeal window with appeals heard within 10-30 days of filing

See Board File No. 201008 for additional details.

Local Program

Also known as Waiver ADUs, this program allows adding ADUs to existing or proposed single- and multi-family buildings (subject to relevant requirements and Codes).

  • When waivers are sought under the Local ADU Program, a Costa-Hawkins Regulatory Agreement may be required. The number of ADUs allowed varies.
  • State law may prevent the City from subjecting some ADUs to the rent stabilization provisions of the San Francisco Rent Ordinance.

See the State Law tab for details.

This program applies to single- and multi-family buildings and offers waivers, or administrative exceptions, to some Planning Code requirements. When these waivers are granted, a Costa-Hawkins Regulatory Agreement may be required, which subjects the ADU(s) to rent control:

Draft Regulatory Agreement: If the subject lot includes Rental Unit(s) (as defined by Section 37.2(r) of the Administrative Code), and Planning Code waivers are granted, the new unit(s) will be subject to rent control. Generally speaking, these existing buildings are already subject to rent-control. A regulatory agreement will be created adding the new ADU(s) under rent control. Please see a sample of the agreement here. The Regulatory agreement will be edited by Planning staff to reflect project specific conditions, and is required to be fully executed prior to permit issuance.

For a history of the legislation, please see these documents and summaries below:

There are two different categories of ADUs under State law:

Streamlined ADUs

Streamlined ADUs are permitted within existing or proposed single-family and multi-family dwellings. They are the most flexible in that compliance with the Planning Code (e.g. rear yard, exposure, etc.) is not required. They are only permitted on properties where there are no other ADUs.

Ministerial ADUs

Ministerial ADUs are permitted within existing or proposed single-family dwellings and existing multi-family dwellings. These ADUs need to comply with Planning Code requirements (e.g. rear yard, exposure, etc.), except for density. They include a new type of ADU called the Junior ADU (JADU).

The following charts provide more details.

View chart as PDF.

ADUs in Single-Family Dwellings (SFD)

ADUs in Multi-Family Dwellings (MFD)

Legalization of Unauthorized Unit

In some cases an ADU already exists on the property without permits. Use this Legalization of Unauthorized Units Checklist to review what items are required. More information is available on the Department of Building Inspection (DBI) website.

Frequently Asked Questions

Disclaimer: This FAQ is for reference only. To ensure you meet all requirements of the Legalization program, please consult the Planning Code or send an email to CPC.ADU@sfgov.org

This information is applicable for property owners of multi-unit buildings and single-family homes with an unwarranted dwelling unit (UDU) on the property who are seeking to legalize the unit.

In 2014, under Ordinance No. 43-14, Planning Code Section 207.3 was established to permit one dwelling unit to be legalized per lot in districts that permit residential use. This is a voluntary program that allows property owners to formally register and rent their unwarranted units in San Francisco assuming all life-safety conditions are met. These additional, existing dwelling units were previously converted by a property owner to turn unused space into a rentable unit. Although it is common, this has been illegal. With this ordinance, one of these existing units may legally join the housing market should the owner follow the process.

This program offers waivers from several areas of the Planning Code in order to legalize the dwelling unit. The Department of Building Inspection (DBI)  maintains a screening program and determines eligibility for enrollment in the legalization program.

* The legalization program can be used in conjunction with the ADU program.