Accessory Dwelling Units

An ADU is a type of residential unit. ADUs are allowed to exceed the allowable density of a lot, which is defined by the zoning district. Some ADUs benefit from exceptions to certain Code requirements and require deed restrictions while density-conforming residential units do not. Check here to decide if an ADU is right for you.

Many ADUs are converted from existing storage or garage space. You may also build an expansion, a stand-alone structure, and add ADUs in conjunction with new construction, depending on the program. Please note that an ADU may not remove housing services, which includes garage, laundry room, storage space, etc., without a “just cause” reason to sever the housing service.

ADUs proposed under the Local Program must provide a Notice of Addition of ADU(s) to unit(s) and a Declaration to the San Francisco Rent Board to ensure housing services are not removed without a “just cause” prior to submittal of an application. Please see here for more details. 

Yes, you may create living space in your home without creating an ADU. You may need to sign the Unauthorized Dwelling Unit Affidavit when you are applying for your building permit to make sure this space won’t be used as another residential unit. 

Each ADU program offers a variety of benefits. Typically, you may be eligible to pick the program that best suits you. However, depending on your property type, location of your ADU, or property history, you may only qualify for one ADU program.

You can pick from a variety of ADU types that are outlined here. After you’ve determined a type of ADU that you would like to add, you can check which program offers your desired ADU and if your property qualifies by looking at the single-family or multi-family tabs.

If you’re still unsure, you can also check with a planner by emailing us at CPC.ADU@sfgov.org.

ADUs in the Local Program may benefit from the following:

• In-house review by Planning* first to facilitate a streamlined building permit review process
• Opportunity to build unlimited ADUs on some multi-family lots or when going through some seismic retrofits
• Receive waivers from certain Planning Code requirements for existing buildings
• Ability to build a Detached ADU in addition to ADU(s) in the primary structure

* Please visit Planning’s Approval webpage for more details. 

ADUs in the Local Program will be subject to the City’s rent control law. These ADUs will not only contribute to the City’s housing stock, but also provides affordable housing units for middle-class households.

ADUs in the State Program benefit from ministerial and streamlined review, which means they are subject to the following:

• Permit Review Roundtable review process
• 60-day review timeframe from date of complete application
• No subjective design review, except for standards that prevent adverse impacts on any real property that is listed in the California Register of Historic Resources
• 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
• Appeals are prohibited under AB 1114 for permits filed on or after January 1, 2024
• State law would prevent the City from subjecting some ADUs to the rent stabilization provisions (rent control) of the San Francisco Rent Ordinance.

* Please visit Planning’s Approval webpage for more details. 

Many rear yard structures can be converted into an ADU if they are built with a building permit or is an existing structure that is no longer allowed under current zoning regulations. Expanding an existing rear yard structure is only allowed if it’s located within the buildable area of your property.

Depending on the existing structure, you may be able to demolish and replace it with a new, freestanding, detached ADU that follows the required setbacks. If the existing structure is used as a legal or unauthorized residential unit, you will be required to receive Planning Commission’s approval for a Conditional Use Authorization prior to demolishing the structure.

If you’re still unsure what to do with your existing structure, you can email us at CPC.ADU@sfgov.org.

Under the Local Program, ADUs cannot be constructed on lots with a residential building that have had owner move-in evictions in the last five (5) years, or other no-fault evictions in the last ten (10) years prior to the permit application. In case of temporary tenant evictions for capital improvements, there is no prohibition as long as a declaration from the property owner was submitted notifying the tenant of their right to reoccupy the unit.

Evictions do not preclude adding an ADU(s) through the State or Hybrid programs.

No. Accessory Dwelling Units are ineligible for the Short-Term Rental program.

Typically no; however, some exceptions apply.

Under the State Program, certain ADUs are eligible for separate sale and conveyance (condo conversion) if they meet all of the following conditions: 

• The lot contains four or fewer existing dwelling units.  
• The application to construct the ADU was submitted on or after 5/1/25.
• Only one ADU is eligible.  
• The ADU is not a Junior ADU.
• The ADU is either:  
  • A State Detached ADU on a property with an existing single-family home or an existing multi-family building that consists entirely of condominiums, or
  • A State Detached or Attached ADU on a property with a new proposed single-family home or new proposed multi-family building that consists entirely of condominiums.  

Under the Local Program, certain ADUs are eligible for separate sale and conveyance (condo conversion) if they meet either of the following conditions: 

• The ADUs are proposed in a building undergoing mandatory seismic retrofitting in compliance with Chapter 4D of the Building Code or voluntary seismic retrofitting in compliance with DBI’s Administrative Bulletin 094.
• The ADUs are proposed in a building that as of July 11, 2013, was an existing condominium and has had no evictions pursuant to Sections 37.9(a) through 37.9(a)12 and 37.9(a)14 of the Administrative Code since July 11, 1996. 

Please review the step-by-step process outlined here.

The Department of Building Inspection (DBI) holds Pre-Application and Pre-Addendum Plan Review Meetings in accordance with DBI Administrative Bulletin AB-028. The Planning Department voluntarily participates in Pre-Application Meetings hosted by DBI for projects that propose Accessory Dwelling Units (ADU).

The Planning Department’s participation in these meetings is not subject to the process or requirements outlined in AB-028 and is provided as a courtesy to the applicant to provide insight into Planning Department requirements in effect at the time of the meeting. These requirements (including the Planning Code, policies, guidelines, etc.) may change over time. As such, the Planning Department’s guidance and responses provided during the meeting, in follow-up communication, and/or reported in the meeting notes are intended to reflect requirements in effect at that time and do not constitute an approval of the project, a final determination regarding Code-compliance, or an official Planning Code Interpretation by the Zoning Administrator.  The feedback provided is based on a preliminary review of information provided by the Applicant and is intended to be advisory only.

If needed, a formal written determination can be requested from the Zoning Administrator through a Letter of Determination. For follow-up questions, please contact us. 

Changes to your approved ADU drawings may require a new building permit application. Some changes can be approved at our Planning Counter while others require in-house review. To learn more, please contact us.