San Francisco ADU Permit Guide 2026

San Francisco recognizes four main ADU categories:

Type	Description	Typical Timeline
Detached ADU	Freestanding structure in the rear yard	12–18 months
Attached ADU	Addition to the main house	10–16 months
Garage Conversion	Converting an existing garage	6–12 months
Junior ADU (JADU)	Room within the existing home ≤500 sq ft	4–8 months

What Changed Under State Law

California ADU law (AB 2221, SB 897, and subsequent bills) overrides many local restrictions when a project qualifies for the State ADU program. Key rules and 2026 updates include:

• Setbacks reduced: Detached ADUs ≤800 sq ft can be placed up to 4 feet from rear and side property lines
• Height increased: Detached ADUs can be up to 16 feet in the rear yard (18 feet if within ½ mile of transit)
• Owner-occupancy: Standard ADUs generally do not carry a local owner-occupancy requirement. JADUs have a narrower rule explained below: owner occupancy applies when a JADU shares sanitation facilities with the main residence.
• Ministerial approval: Qualifying State ADUs receive ministerial review. San Francisco Planning lists no CEQA review, no Planning Code Section 311 neighborhood notification, no discretionary-review opportunity, and no public appeal opportunity for that pathway; SB 543 separately requires a process for an applicant to appeal an incomplete or denied application. Attached ADUs under California Government Code Section 66314 are the listed exception to the usual ban on subjective design review.

2026 updates: SB 543 and AB 1154

SB 543 — completeness and review deadlines. Effective January 1, 2026, SB 543 requires a permitting agency to provide a written completeness determination for an ADU or JADU application within 15 business days of receiving it. If the agency does not make that determination on time, the application is deemed complete for this purpose.

For a completed application on a lot with an existing single-family or multifamily dwelling, the agency must approve or deny the ADU or JADU application within 60 days. A different timing rule can apply when the ADU application is submitted with an application for a new primary dwelling. SB 543 also requires an appeal process when an application is found incomplete or denied.

These deadlines are important safeguards, not a permission to start construction without an issued permit. Save your dated submission, completeness notice, and all correction correspondence; if a deadline appears to have passed, ask San Francisco Planning or DBI to confirm the application status and next step in writing.

AB 1154 — JADU owner occupancy depends on sanitation facilities. Also effective January 1, 2026, AB 1154 limits a local owner-occupancy requirement to JADUs that share sanitation facilities with the existing residence. If the JADU has separate sanitation facilities, owner occupancy is not required. The statute also exempts government agencies, land trusts, and housing organizations from that requirement, and requires JADU rentals to be for a term longer than 30 days.

The Two Agencies: Planning and DBI

Every San Francisco ADU touches two city departments:

San Francisco Planning Department reviews your project for zoning compliance — setbacks, heights, lot coverage, and objective design standards. For qualifying State ADUs, San Francisco Planning lists a 60-day review from the date of a complete application; the full project schedule can still depend on submission quality, DBI review, trade permits, utilities, and construction.

Department of Building Inspection (DBI) issues the actual building permit and conducts construction inspections.

Some projects also require:

• San Francisco Public Utilities Commission (SFPUC): Water and sewer connection approvals
• SFFD (Fire Department): Electrical permits for new service
• PG&E: Utility connections (separate from city permits)

Permit Types by ADU Category

Detached ADU Permits

A new freestanding ADU requires the most permits of any ADU type:

1. Planning Review (Zoning): Qualifying State ADUs are reviewed ministerially. Projects outside that path, or with site-specific requirements, can have different Planning review needs.
2. DBI Building Permit (New Construction): The primary permit. Requires full plan set, structural engineering for foundation, and energy compliance documentation.
3. Plumbing Permit: For all supply, drain, and gas lines.
4. Electrical Permit (SFFD): For new electrical service to the ADU.
5. Mechanical Permit: For HVAC systems.

Fees for a 600 sq ft Detached ADU:

Fee	Estimated Amount
DBI Building Permit	$3,200–$5,800
Plan Check	$2,080–$3,770
Planning Application	$3,000–$6,000
Plumbing Permit	$1,400–$2,200
Electrical Permit	$800–$1,400
SFPUC Connection	$8,000–$18,000
School Impact Fee	$4,100 (waived for ADUs ≤500 sq ft)
Total Permits & Fees	$22,000–$57,000

The SFPUC connection fee is the biggest variable — it depends on your lot's existing sewer capacity.

Garage Conversion ADU Permits

Converting a garage to a living unit is the most popular ADU path in San Francisco because existing structure reduces costs and permits.

1. DBI Alteration Permit: For structural modifications, insulation, new windows/doors.
2. Plumbing Permit: Required if adding a kitchen or bathroom.
3. Electrical Permit: Required for upgraded electrical service or new circuits.
4. Planning Review: Qualifying State ADUs use a ministerial path; confirm the applicable program and project-specific conditions before filing.

Fees for a 350 sq ft Garage Conversion:

Fee	Estimated Amount
DBI Alteration Permit	$1,400–$2,800
Plan Check	$910–$1,820
Plumbing Permit	$800–$1,600
Electrical Permit	$500–$900
Total	$3,600–$7,120

Note: If the garage is attached to the main house with a shared wall, additional fire separation requirements (1-hour fire wall) may increase construction costs.

Junior ADU (JADU) Permits

JADUs are the fastest path to a legal additional unit. They're created within the existing home's footprint — typically a bedroom with an efficiency kitchen added.

JADU requirements under state law:

• Maximum 500 sq ft
• Must include an exterior entrance (separate from main house)
• Must include an efficiency kitchen (no full stove required)
• Does not require a separate bathroom if the main home's bathroom is accessible
• If it shares sanitation facilities with the main residence, the owner must record the required deed restriction and occupy either the JADU or the remaining single-family home
• If it has separate sanitation facilities, owner occupancy is not required; government agencies, land trusts, and housing organizations are also exempt from the owner-occupancy requirement
• A JADU rental term must be longer than 30 days

1. DBI Alteration Permit: For any construction work.
2. Plumbing Permit: If adding kitchen sink or new fixtures.
3. Electrical Permit: If adding new circuits.
4. No separate Planning permit is required for ministerial JADUs.

Fees for a 450 sq ft JADU:

Fee	Estimated Amount
DBI Alteration Permit	$800–$1,600
Plumbing Permit	$400–$700
Electrical Permit	$300–$550
Total	$1,500–$2,850

The ADU Permit Process Step by Step

1. Pre-Application Meeting (optional but recommended): San Francisco Planning offers a pre-application meeting for $500–$800. For complex sites (hillside lots, historic districts), this can save months of back-and-forth later.

2. Submit and document your application: File the required plans and zoning materials through the applicable City process. For qualifying ADUs and JADUs, SB 543 requires a written completeness determination within 15 business days; keep dated copies of your submission and any correction notice.

3. Planning review and corrections: For a completed application on a lot with an existing dwelling, state law requires an approval or denial within 60 days. Respond to correction notices promptly and use the City’s appeal process if an application is found incomplete or denied; do not begin work until the required permits are issued.

4. Submit to DBI: File your building permit application with full plan set (architectural drawings, structural calculations, energy compliance, Title 24 documentation).

5. DBI Plan Review: Standard review takes 8–16 weeks. Expedited review (150% fee) can reduce this to 2–4 weeks.

6. Permit Issued: Pay remaining fees, receive your permit card. Post it on-site before breaking ground.

7. Construction Inspections: DBI requires inspections at foundation, framing, rough plumbing/electrical, and final. Schedule at least 5–7 business days ahead.

8. Final Inspection and Certificate of Occupancy: After all work passes inspection, DBI issues a Certificate of Final Completion.

Common ADU Permit Pitfalls

Rear yard calculation errors: San Francisco requires that the rear yard (typically 25–45% of lot depth) remain unobstructed. A planning rejection for rear yard violations is one of the most common ADU setbacks.

Parking replacement: State law prohibits San Francisco from requiring parking replacement for ADUs in most cases, but some projects may still trigger it. Confirm during pre-application review.

Historic and site-specific conditions: The State ADU path has ministerial protections, but eligibility and applicable standards depend on the project type and site. Do not assume that an historic designation, an attached addition, or another project-specific condition has the same review path as a qualifying converted or detached State ADU; confirm the current requirements with San Francisco Planning before relying on a timeline.

Utility capacity: The SFPUC conducts a water/sewer capacity analysis for all new units. If your main connection needs upgrading, costs escalate significantly.

2026 ADU law sources

• SB 543 — California Legislative Information
• AB 1154 — California Legislative Information
• San Francisco Planning Director's Bulletin No. 3: State Accessory Dwelling Unit Program
• San Francisco Planning: Accessory Dwelling Units