Two clocks run: the permit and the build. For a complete application, California requires a decision within 60 days, and as of November 2026 a completeness check within 15 business days. Design before that and construction after it take longer, and the lot, the plan and how fast corrections are answered decide the total.
Where does the time go?
- Lot check and design. Survey, layout, structural and energy work. Pre-approved plans can shorten this.
- Plan check. Submittal, completeness review, corrections and resubmittal.
- Utility work. Sewer, water and electrical capacity, sometimes with the utility on its own schedule.
- Construction and inspections. Foundation, framing, rough inspections, finishes, final.
What speeds things up?
- A complete first submittal, with the survey and utility routes worked out.
- A plan that already fits the setbacks and height limits.
- Quick answers to plan check comments.
- Choosing a conversion over new construction when the structure is sound.
San Francisco notes
The State Program runs through the Permit Review Roundtable with a 60-day review from a complete application. The Local Program adds the Notice of Addition and Rent Board declaration before submittal. Ground-floor conversions in older buildings often find structural surprises once walls open.
Sources, as of November 2026: California Government Code section 66310 and following (ADU law), including SB 543 (2025); California Department of Housing and Community Development, ADU Handbook. General information, not legal advice. San Francisco Planning, "Accessory Dwelling Units".
Updated November 2026