Permit Required? Required
Typical Fee Range $1,500–$8,000 Impact fees are waived for ADUs under 750 square feet as of 2026.
Fee Method Valuation-based
Apply Online Apply at San Francisco Department of Building Inspection →

What's Required in San Francisco

  • Permit required for all Accessory Dwelling Units (ADUs), conversion or new
  • Impact fees (park, school, traffic) waived for units under 750 square feet
  • Owner-occupancy requirement permanently removed for ADUs and JADUs as of 2026
  • Detached ADUs are allowed up to 16–18 feet in height depending on transit proximity
  • Minimum 4-foot rear and side yard setbacks required
  • Public notice (15 days) required for units using the 'Local ADU Program'

How Much Does an ADU Permit Cost in San Francisco?

Budget $1,500–$8,000 for the San Francisco permit itself (valuation-based), issued by the San Francisco Department of Building Inspection — but treat that as the entry fee, not the total. ADUs are full dwelling units, so the permit stack usually includes building, electrical, plumbing, and mechanical trade permits, plus plan review. One break on record here: impact fees are waived for ADUs under 750 square feet as of 2026. Get an itemized fee estimate from the department before finalizing your budget; the spread between a simple conversion and a new detached build is wide.

ADU Size Limits and Zoning Rules in San Francisco

Before drawing plans, check the two gates that sink most ADU projects: size and zoning. Size ceilings vary by lot and ADU type (attached, detached, or conversion), so confirm your specific configuration. Other recorded conditions: owner-occupancy requirement permanently removed for ADUs and JADUs as of 2026; detached ADUs are allowed up to 16–18 feet in height depending on transit proximity. Setbacks, height limits, and utility connections layer on top of those rules. The San Francisco Department of Building Inspection can confirm what your specific lot allows — worth doing before you pay for architectural drawings rather than after.

How to Get a ADU Permit in San Francisco

1

Step 1: Program Consultation

Consult a planner to determine if the 'State' or 'Local' ADU program applies.

2

Step 2: Plan Design

Prepare architectural, structural, and Title 24 energy plans.

3

Step 3: PRJ Submittal

Submit a Project Application to SF Planning before building permit filing.

4

Step 4: Fee Payment

Pay building fees and any proportional impact fees for units > 750 sq ft.

5

Step 5: Construction Inspections

Schedule the full sequence: Foundation, Framing, Rough MEP, and Final.

Frequently Asked Questions

Yes, ADUs are allowed on most residential lots; impact fees are waived for units < 750 sq ft.
Building fees start at $1,500; total costs exceed $5,000 for units over 750 sq ft.
No, 2026 state law permanently prohibits owner-occupancy requirements.
Impact fees are waived for ADUs under 750 square feet as of 2026.