How the San Francisco ADU permit process works — design, engineering, planning and code review, building permit, structural and MEP inspections, and final sign-off.
An ADU permit runs through design, structural engineering, planning and code review where applicable, building permit submission, a review and correction loop, then permit issue. During construction, work holds for foundation, framing and MEP inspections before anything is covered, and finishes with a final inspection.
Requirements change. This guide explains the shape of the process — what happens, in what order, and who is responsible at each stage — rather than stating specific current code requirements, which should be confirmed with the City and with your design team at the time you apply.
Leafair is a licensed general contractor. It coordinates the permit and the inspection holds during construction. It does not produce the drawings or the structural calculations, and it does not interpret code on your behalf.
| Stage | What happens |
|---|---|
| Design | Architect produces drawings that satisfy the layout, the site constraints and the applicable requirements. |
| Structural engineering | Engineer produces stamped drawings and calculations for anything carrying load. |
| Planning and code review | Where applicable, the proposal is reviewed against planning and zoning requirements before or alongside the building permit. |
| Building permit application | The full drawing set is submitted for review. |
| Review and corrections | Comments come back, the design team responds, and the set is resubmitted as needed. This loop is normal. |
| Permit issued | Construction can begin. Not before. |
| Structural inspections | Foundation reinforcement is inspected before concrete is poured. Framing is inspected before it is covered. |
| MEP inspections | Plumbing, electrical and mechanical rough-in inspected while still open. |
| Insulation and cover | Only after rough-in has passed. |
| Final inspection | The completed unit is inspected and signed off. |
Who submits the application and who responds to review comments. Whether engineering is included in the design fee or separate. What happens to the construction schedule if review runs long. Who calls the inspections during construction, and what the process is when something fails.
How to build an ADU in San Francisco and what drives ADU cost. To discuss a property, see ADU construction with Leafair.
Yes. An ADU is a new dwelling unit and is permitted, reviewed and inspected work. Anyone offering to build one without a permit is offering you a problem at resale.
It varies and it is outside a contractor's control. Treat it as a genuine schedule item. Nothing should be ordered or trades booked on the assumption that review will be quick.
Work stops at defined points so an inspector can see what is about to be covered — typically foundation reinforcement before the pour, and framing and MEP rough-in before insulation and drywall. Work that gets covered before sign-off may have to be opened again.
Leafair will walk the site, talk through what is realistic, and give you a written estimate priced line by line. Estimates are free.
