Planning Director Bulletin No. 3: State Accessory Dwelling Unit Program

This bulletin is an overview of the State Accessory Dwelling Unit (ADU) Program implemented in San Francisco. Refer to Planning Code Section 207.1 and resources available on the SF.gov website for the Local ADU Program.

First Issued: August 2025, updated February 2026
References: California Government Code Section 66314 through 66333 Planning Code Section 207.2

Background

Overview

ADUs, also called secondary units, in-law units, or cottages, are units added to existing and new residential buildings. Adding an ADU to a property can provide several benefits, such as providing housing for family members, simplifying a lifestyle, and increasing financial flexibility. CA Govt. Code Section 66313 defines an ADU as:

"Accessory dwelling unit" means an attached or a detached residential dwelling unit that provides complete independent living facilities for one or more persons and is located on a lot with a proposed or existing primary residence. It shall include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the single-family or multifamily dwelling is or will be situated. An accessory dwelling unit also includes the following: (1) an efficiency unit and (2) a manufactured home, as defined in Section 18007 of the Health and Safety Code.

CA Govt. Code Section 66313 defines a Junior ADU (JADU) as:

"Junior accessory dwelling unit" means a unit that is no more than 500 square feet in size and contained entirely within a single-family residence. A junior accessory dwelling unit may include separate sanitation facilities, or may share sanitation facilities with the existing structure.

There are four ADU types:

1. Converted ADUs, sometimes referred to as interior ADUs, are new units located in a residential building.
2. Attached ADUs are new units that expand a residential building.
3. Detached ADUs are new free-standing buildings located on a residential property.
4. Junior ADUs (JADU) are a new type of ADU that convert up to 500 square feet of space in a single-family structure. JADUs may include separate sanitation facilities or may share sanitation facilities with the existing structure.

Eligibility

• Zoning. The lot must be located in a zoning district that allows residential use, including single- and multifamily use. To determine a parcel's zoning district, please consult the Property Information Map.
• Use. The lot must contain an existing or proposed dwelling.
• Historic Resources. ADUs proposed under CA Govt. Code Section 66314 on properties that are listed in the California Register of Historic Places or properties designated individually or as part of a historic or conservation district per Article 10 or 11 of the Planning Code must be consistent with standards that prevent adverse impacts on the historic resource.
• Prohibition of Short-Term Rentals. The rental of any ADU must be for a term longer than 30 days.

Separate Sale or Conveyance (Condo Conversion) Eligibility

Certain ADUs are eligible for separate sale or 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 May 1, 2025.
• 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 building 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 building or new proposed multi-family building that consists entirely of condominiums.

Program Requirements - Single-Family Building

Types of ADUs

• Detached ADU
• Converted ADU
• Junior ADU (JADU)
• Attached ADU

Number of ADUs. Number of ADUs varies, please see details below under each ADU type.

• Detached, Converted, and JADUs may be combined.
• Attached ADU may not be combined with other ADU types.

Taking space away from existing unit. Converted ADU and JADU may take space away from the existing single-family building.

Commercial conversion. State ADUs cannot convert commercial space.

Access. Independent entrance is required.

Kitchen. A full kitchen is required for an ADU, which shall include permanent provisions for eating and cooking. A partial kitchen is required for an ADU that is an efficiency unit or JADU.

Planning Code compliance. State ADUs are exempt from compliance with the local Planning Code except for standards in Planning Code Section 207.2; however, any work not related to the ADU is subject to the Planning Code.

Detached ADU (Ca Govt. Code Section 66323)

• Number of ADUs. 1 Detached ADU is allowed on a lot with an existing or proposed single-family building. This ADU may be combined with a Converted and Junior ADU.
• Maximum size. Studio and 1-bedroom ADUs are allowed up to 850 square feet. 2+ bedroom ADUs are allowed up to 1,000 square feet.
• Maximum height. Up to 18 feet. An additional 2 feet is allowed to accommodate a roof pitch that is aligned with the roof pitch of the primary dwelling unit.
• Rear and side setbacks. A 4-foot setback is required from side and rear lot lines. No setback is required if the ADU replaces an existing structure and is located in the same location and constructed to the same dimensions, including height, as the structure being replaced.

Converted ADU (Ca Govt. Code Section 66323)

• Number of ADUs. 1 Converted ADU is allowed on a lot with an existing or proposed single-family building. This ADU may be combined with a Detached and Junior ADU.
• Maximum size, maximum height, and setbacks. No requirements apply since a Converted ADU is restricted based on available or desired space for conversion.
• Expansions. When an existing auxiliary structure is proposed for conversion into a State ADU, an expansion of up to 150 square feet is allowed only to accommodate ingress and egress.
• Access. Must have exterior access.

JADU (Ca Govt. Code Section 66333)

• Number of ADUs. 1 JADU is allowed on a lot with a single-family building. This ADU may be combined with a Converted and Detached ADU.
• Maximum size. Up to 500 square feet of interior livable space.
• Maximum height and setbacks. No requirements apply since JADU is restricted based on available or desired space for conversion.
• Kitchen. At least an efficiency kitchen is required, which shall include all of the following: a cooking facility with appliances and a food preparation counter and storage cabinets that are of reasonable size in relation to the size of the JADU.
• Deed restriction. If the JADU shares sanitation facilities (bathroom) with the main residence, the owner of the property must record a deed restriction to include the requirements listed in Government Sections 66323 and 66333, which include an owner occupancy requirement either in the JADU or the primary single-family home.

Attached ADU (Ca Govt. Code Section 66314)

• Number of ADUs. 1 Attached ADU is allowed on a lot with an existing or proposed single-family building. This ADU may not be combined with other ADU types.
• Maximum size. Studio and 1-bedroom ADUs are allowed up to 850 square feet or up to 50% of the existing primary dwelling, whichever is greater, of interior livable space. 2+ bedroom ADUs are allowed up to 1,000 square feet or up to 50% of the existing primary dwelling, whichever is greater, of interior livable space.
• Maximum height. Up to 25 feet.
• Rear and side setbacks. When expanding an existing building, a 4-foot setback is required from side and rear lot lines. When the ADU is proposed as part of new construction, a 4-foot setback is required from side and rear lot lines for portions of the ADU outside of the buildable area.

Program Requirements - Multi-Family Buildings

Types of ADUs

• Detached ADU
• Converted ADU
• Attached ADU

Number of ADUs. Number of ADUs varies, please see details below under each ADU type.

• Detached and Converted ADUs may be combined.
• Attached ADU may not be combined with other ADU types.

Taking space away from existing unit. State ADUs cannot take space away from any existing unit in a multi-family building.

Commercial conversion. State ADUs cannot convert commercial space.

Access. Independent entrance is required.

Kitchen. A full kitchen is required unless the ADU is an efficiency unit, which requires a partial kitchen.

Detached ADU (Ca Govt. Code Section 66323)

• Number of ADUs. 2 Detached ADUs on a lot with a proposed multi-family building. Up to 8 Detached ADUs but not more than the number of existing units on the lot if located on a lot with an existing multi-family building.
• Maximum size. No maximum size.
• Maximum height. Up to 18 feet. An additional 2 feet is allowed to accommodate a roof pitch that is aligned with the roof pitch of the primary dwelling unit.
• Rear and side setbacks. A 4-foot setback is required from side and rear lot lines. No setback is required if the ADU replaces an existing structure.

Converted Adu (Ca Govt. Code Section 66323)

• Number of ADUs. 1 Converted ADU or up to 25 percent of the number of existing dwelling units in the multi-family building on a lot with an existing multi-family building.
• Maximum size, maximum height, and setbacks. No requirements apply since a Converted ADU is restricted based on available or desired space for conversion.
• Existing space. Converted ADUs are only allowed within existing multi-family buildings and may only convert non-livable space.

Attached ADU (Ca Govt. Code Section 66314)

• Number of ADUs. 1 ADU is allowed on a lot with an existing or proposed multi-family building. This ADU may not be combined with other ADU types.
• Maximum size. Studio and 1-bedroom ADUs are allowed up to 850 square feet or up to 50% of the existing primary dwelling, whichever is greater. 2+ bedroom ADUs are allowed up to 1,000 square feet or up to 50% of the existing primary dwelling, whichever is greater.
• Maximum height. Up to 25 feet.

Process

State ADUs benefit from ministerial review. This includes:

• 60-day review from the date of a complete application.
• Not subject to review under the California Environmental Quality Act (CEQA).
• No subjective design review except for ADUs proposed under CA Govt. Code Section 66314.
• Not subject to Planning Code Section 311 neighborhood notification requirements.
• No discretionary review (DR) opportunity.
• No appeal opportunity.

Impact Fees

ADUs and JADUs smaller than 750 square feet of interior livable space or on lots with 3 existing units or fewer are exempt from impact fees. When impact fees apply, they are imposed proportionately in relation to the gross floor area of the primary dwelling unit.