The Fastest Bay Area Cities for ADU Permits (2026 Data)

Every California city follows the same state ADU law, but they don't move at the same speed. State law gives a city 60 days to approve or deny a complete ADU application. In practice, the clock pauses each time the city sends corrections back, and many projects go through two or three rounds.

The public numbers below come from cities' annual reports to the California Department of Housing and Community Development, matched permit by permit from application to issuance. Some cities, including Berkeley and the city of San Mateo, were left out of that analysis because of gaps in their reporting.

Across 15 Type Five projects first submitted between June 2025 and May 2026 that now have a building permit, the median time from first submittal to issued permit was 120 days. The fastest took 50 days and the slowest 196. Six of the 15 were issued within 90 days and eight within 120.

A few caveats. Fifteen permits is a small sample. It only counts projects that already have a permit, so slower projects still in review aren't in it yet, which makes the numbers look faster. And most cities below have just one or two of our permits, so each row is a single project's experience, not a city average.

• Correction rounds. The 60-day clock stops whenever plans go back for changes. Fewer rounds is the biggest lever you have.
• Other departments. Fire, public works, sewer and urban forestry reviews can run in parallel or one after another, depending on the city.
• Site conditions. Hillsides, fire hazard zones, protected trees and sewer upgrades add reviewers and documents.
• Staffing and workload. A city can be fast one year and slow the next. The Bay Area median rose from 113 days in 2022 to 182 days in 2024.

• Check the city's rules before design starts. Setbacks, height, trees and parking rules differ a lot even between neighboring towns. Our city guides below summarize them.
• Submit a complete, coordinated set. Structural, energy and site plans that agree with each other draw fewer comments.
• Answer corrections quickly. Every week your plans sit with you is a week the permit isn't moving.
• Use a team that does it all. When the designer and builder are the same company, plan check answers don't wait on a handoff.

Some cities also offer pre-approved or permit-ready ADU plans. They can save design time on simple lots, but they don't remove site review. See our Los Altos page for one example.

A permit is the midpoint, not the finish line. Type Five builds every ADU on site with conventional wood framing, and our build schedule page shows how construction is sequenced from foundation to final inspection.

Planning a budget too? Our Bay Area ADU cost guide breaks down design, permit fees, site work and construction.