San Francisco County brings city and county services together within one compact urban area. This page introduces the region’s ADU resources and connects visitors with the detailed San Francisco jurisdiction profile.
Incorporated cities inside San Francisco County adopt their own ADU standards, so a property inside city limits follows that city's rules. County standards apply to the unincorporated areas.
Rules are grouped by topic. Open a topic for the answers, the conditions on them, and the official source each one came from. Each rule names the authority that set it: Statewide standard and San Francisco County standard.
Filter
61 rules
What can I build?
The kinds of accessory dwelling unit this jurisdiction recognises.10 rules
Detached ADU allowed
Allowed
Detached ADUs are authorized on the same lot as a proposed or existing primary dwelling.
Set by: Statewide standard
In force from: Effective
Explanation
Whether a detached, newly constructed ADU is permitted.
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code § 66314(d)(3)
Source document
California Government Code, Title 7, Division 1, Chapter 13
One qualifying detached ADU is allowed in the required rear yard in addition to local-program ADUs within the primary structure.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Up to 2 count
A lot with a proposed multifamily dwelling may have up to two detached ADUs.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Up to 8 count
An existing multifamily lot may have up to eight detached ADUs, but no more than its existing dwelling-unit count.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Up to 1 count
One detached new-construction ADU is ministerially allowed on a qualifying single-family lot.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Where a topic is recorded at more than one level, both entries are shown with the authority that set them. Which one governs a particular property is a question for the responsible planning agency.
Explanation — San Francisco County standard
Greatest number of detached ADUs permitted on the property.
When this applies
Applies when all of the following are true:
Property existing unit count is at most 4
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — Statewide standard
Greatest number of detached ADUs permitted on the property.
When this applies
Applies when all of the following are true:
Property primary structure type is Multifamily
Property has existing primary dwelling is no
Part of Statewide, published by California.
Explanation — Statewide standard
Greatest number of detached ADUs permitted on the property.
When this applies
Applies when all of the following are true:
Property primary structure type is Multifamily
Property has existing primary dwelling is yes
Part of Statewide, published by California.
Explanation — Statewide standard
Greatest number of detached ADUs permitted on the property.
When this applies
Applies when all of the following are true:
Property primary structure type is Single family
Part of Statewide, published by California.
Source — San Francisco County standard
San Francisco Planning Code § 207.1 — Local Accessory Dwelling Unit Program, § § 207.1(c)(15)
Source document
San Francisco Planning Code § 207.1 — Local Accessory Dwelling Unit Program
Smaller qualifying properties may receive one local-program ADU plus one qualifying detached rear-yard ADU; larger properties may have no local-program numerical cap.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Explanation
Greatest number of ADUs permitted on the property, counting all types.
When this applies
Applies when all of the following are true:
Property existing unit count is at most 4
Part of San Fransisco County Local Rules, published by San Francisco County.
Sources (2)
San Francisco Planning Code § 207.1 — Local Accessory Dwelling Unit Program, § § 207.1(c)(1)
Source document
San Francisco Planning Code § 207.1 — Local Accessory Dwelling Unit Program
An ADU is a residential use consistent with the lot's existing general-plan and zoning designations where the lot allows single-family or multifamily residential use.
Explanation
Whether the zoning district permits ADUs.
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code § 66314(c)
Source document
California Government Code, Title 7, Division 1, Chapter 13
An ADU with more than one bedroom is limited to 1,000 square feet under the cited local state-mandated-program provisions.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Up to 850 sqft
A one-bedroom-or-smaller ADU is limited to 850 square feet under the cited local state-mandated-program provisions.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Up to 1,200 sqft
A detached ADU may not exceed 1,200 square feet under the statewide baseline.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Where a topic is recorded at more than one level, both entries are shown with the authority that set them. Which one governs a particular property is a question for the responsible planning agency.
Explanation — San Francisco County standard
Greatest permitted floor area of the ADU.
When this applies
Applies when all of the following are true:
Project unit type is one of Detached adu, Attached adu
Project bedrooms is more than 1
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — San Francisco County standard
Greatest permitted floor area of the ADU.
When this applies
Applies when all of the following are true:
Project unit type is one of Detached adu, Attached adu
Project bedrooms is at most 1
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — Statewide standard
Greatest permitted floor area of the ADU.
When this applies
Applies when all of the following are true:
Project unit type is Detached adu
Part of Statewide, published by California.
Source — San Francisco County standard
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program, § § 207.2(c)(1), § 207.2(d)(5)
Source document
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program
The local ADU size limit changes above one bedroom.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
At least 1,000 sqft
A local maximum size rule may not be lower than 1,000 square feet for an ADU with more than one bedroom.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Where a topic is recorded at more than one level, both entries are shown with the authority that set them. Which one governs a particular property is a question for the responsible planning agency.
Explanation — San Francisco County standard
Floor area at which a different bedroom limit or size allowance takes effect.
When this applies
Applies when all of the following are true:
Project bedrooms is at most 1
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — Statewide standard
Floor area at which a different bedroom limit or size allowance takes effect.
When this applies
Applies when all of the following are true:
Project bedrooms is more than 1
Part of Statewide, published by California.
Source — San Francisco County standard
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program, § § 207.2(c)(1)
Source document
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program
How tall an ADU may be, and how many storeys.6 rules
Maximum height
Up to 18 ft
A detached ADU may be up to 18 feet high.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Up to 25 ft
An attached ADU must be allowed up to 25 feet or the primary dwelling's applicable zoning height, whichever is lower; it need not exceed two stories.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Up to 16 ft
A local height limit must allow at least 16 feet for a detached ADU, subject to more favorable transit and multifamily rules.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Where a topic is recorded at more than one level, both entries are shown with the authority that set them. Which one governs a particular property is a question for the responsible planning agency.
Explanation — San Francisco County standard
Greatest permitted height of the ADU.
When this applies
Applies when all of the following are true:
Project unit type is Detached adu
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — Statewide standard
Greatest permitted height of the ADU.
When this applies
Applies when all of the following are true:
Project unit type is Attached adu
Part of Statewide, published by California.
Explanation — Statewide standard
Greatest permitted height of the ADU.
When this applies
Applies when all of the following are true:
Project unit type is Detached adu
Part of Statewide, published by California.
Source — San Francisco County standard
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program, § § 207.2(d)(9)(A)
Source document
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program
Publisher
San Francisco County
Document type
ADU webpage
Source type
Binding law
Section
§ 207.2(d)(9)(A)
Source checked
August 27, 2026
Excerpt
A height of 18 feet for a detached ADU on a lot with an existing or proposed dwelling.
Connections, meters and the charges that come with them.8 rules
Separate utility meter required
Not required
For qualifying conversion ADUs and JADUs, a new or separate direct utility connection may not be required except with a new single-family dwelling or separate conveyance.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Explanation
Whether the ADU must have its own utility meter.
When this applies
Applies when all of the following are true:
Project construction type is one of Interior conversion, Accessory structure conversion, Garage conversion
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code § 66311.5(d)
Source document
California Government Code, Title 7, Division 1, Chapter 13
ADUs and JADUs on lots with three or fewer existing units are exempt from local impact fees.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Yes
A JADU of 500 square feet or less is exempt from impact fees.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Yes
An ADU of 750 square feet or less is exempt from impact fees.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Where a topic is recorded at more than one level, both entries are shown with the authority that set them. Which one governs a particular property is a question for the responsible planning agency.
Explanation — San Francisco County standard
Whether the ADU is exempt from development impact fees.
When this applies
Applies when all of the following are true:
Property existing unit count is at most 3
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — Statewide standard
Whether the ADU is exempt from development impact fees.
When this applies
Applies when all of the following are true:
Project unit type is Jadu
Project proposed size sqft is at most 500
Part of Statewide, published by California.
Explanation — Statewide standard
Whether the ADU is exempt from development impact fees.
When this applies
Applies when all of the following are true:
Project unit type is one of Detached adu, Attached adu, Conversion adu
Project proposed size sqft is at most 750
Part of Statewide, published by California.
Source — San Francisco County standard
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program, § § 207.2(j)
Source document
San Francisco Planning Code § 207.2 — State Mandated Accessory Dwelling Unit Program
A completed ADU or JADU application on a lot with an existing qualifying dwelling must be approved or denied within 60 days; applicant-requested delay tolls the period.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Explanation
Longest period the agency may take to approve or deny a completed application. Frequently scoped to lots with an existing dwelling; that condition belongs in the claim's applicability, not in this description.
When this applies
Applies when all of the following are true:
Property has existing primary dwelling is yes
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code §§ 66317(a)(3), 66335(a)(3)
Source document
California Government Code, Title 7, Division 1, Chapter 13
Maximum period to act on a coastal development permit
Up to 60 days
A completed coastal development permit application for an ADU must be approved or denied within 60 days, subject to the concurrent-primary-dwelling exception.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Explanation
Longest period the agency may take to act on a coastal development permit application. Separate from the underlying ADU application timeline.
When this applies
Applies when all of the following are true:
Property overlays includes Coastal overlay
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code § 66329(a)
Source document
California Government Code, Title 7, Division 1, Chapter 13
For a detached garage replaced by an ADU, written notice or placarding for demolition cannot be required outside an architecturally and historically significant historic district.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Explanation
Whether a demolition permit review or delay applies to the project.
When this applies
Applies when all of the following are true:
Property overlays does not include Historic district
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code § 66314(f)
Source document
California Government Code, Title 7, Division 1, Chapter 13
San Francisco has a local process to legalize certain unpermitted dwelling units in existing residential buildings or ancillary structures.
Set by: San Francisco County standard
Note: Conditions apply
Yes
An unpermitted ADU or JADU built before January 1, 2020 has a statewide permit pathway, subject to health-and-safety exceptions.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Where a topic is recorded at more than one level, both entries are shown with the authority that set them. Which one governs a particular property is a question for the responsible planning agency.
Explanation — San Francisco County standard
Whether an existing unpermitted ADU can be brought into compliance under a legalization pathway.
When this applies
Applies when all of the following are true:
Project construction type is Legalization
Part of San Fransisco County Local Rules, published by San Francisco County.
Explanation — Statewide standard
Whether an existing unpermitted ADU can be brought into compliance under a legalization pathway.
When this applies
Applies when all of the following are true:
Project construction type is Legalization
Part of Statewide, published by California.
Source — San Francisco County standard
San Francisco Planning Code § 207.3 — Authorization of Dwelling Units Constructed Without a Permit, § § 207.3
Source document
San Francisco Planning Code § 207.3 — Authorization of Dwelling Units Constructed Without a Permit
Publisher
San Francisco County
Document type
ADU webpage
Source type
Binding law
Section
§ 207.3
Source checked
August 27, 2026
Excerpt
certain dwelling units that were constructed without benefit of permit in an existing residential building or in an ancillary structure located on the same lot may be granted legal status
An ADU or JADU generally may not be sold separately from the primary residence, subject to a statutory separate-conveyance exception not captured by this broad rule.
Set by: Statewide standard
In force from: Effective
Note: Conditions apply
Explanation
Whether the ADU may be sold separately from the primary dwelling.
When this applies
Applies when all of the following are true:
Project separate sale intended is yes
Part of Statewide, published by California.
Source
California Government Code, Title 7, Division 1, Chapter 13, § Gov. Code § 66314(d)(1)
Source document
California Government Code, Title 7, Division 1, Chapter 13
A JADU generally requires owner occupancy, subject to specified organizational-owner exceptions.
Set by: San Francisco County standard
In force from: Effective
Note: Conditions apply
Explanation
Whether the owner must occupy the primary dwelling or the ADU.
When this applies
Applies when all of the following are true:
Project unit type is Jadu
Part of San Fransisco County Local Rules, published by San Francisco County.
Source
San Francisco Planning Code § 102 — Definitions, § Definition of Dwelling Unit, Junior Accessory, or JADU
Source document
San Francisco Planning Code § 102 — Definitions
Publisher
San Francisco County
Document type
ADU webpage
Source type
Binding law
Section
Definition of Dwelling Unit, Junior Accessory, or JADU
Source checked
August 27, 2026
Excerpt
is owner-occupied, unless the owner resides in the remaining portion of the structure; provided, however, that owner-occupancy shall not be required if the owner is a governmental agency, land trust, or housing organization
ADUDesk summarises recorded rules for informational purposes and may not include every requirement. Confirm current requirements with the responsible planning agency before making design, purchase, or permit decisions.
About this information
Dates, versions and how rules are recorded
Rules are recorded from official sources and each one links to the document it came from. A source check confirms the document was retrieved and read; it is not a legal review, and the record may not cover every requirement that applies to a property or project.
Report as of
The date the rules on this page were resolved for.
Jurisdiction record reviewed
Not recordedWhen this jurisdiction's record was last checked. Not a legal review.
Statewide
Published by California
Rule-set effective from
Published
Statewide rules reviewed
A staff check of this rule set against its sources.
What changed in this version: Initial
San Fransisco County Local Rules
Published by San Francisco County
Rule-set effective from
Published
Local rules reviewed
A staff check of this rule set against its sources.
What changed in this version: Created from V2 research draft #9 (run #25).
