Can California Cities Still Slow-Walk Your Building Permit? A New Law Says No

Quick answer

If you've ever waited months on a building permit for a remodel, ADU, or new home in Ventura County, California just passed a law aimed at that exact problem. AB 1621 puts real limits on how long local agencies can sit on post-entitlement building permits, caps how many times they can send you back for resubmittals, and gives applicants a court remedy if a city blows past its deadline. It's a process-speed law, not a guarantee every project gets easier or cheaper.

What is AB 1621, and why does it matter here?

AB 1621 goes after a specific, very practical headache: the permit process that happens after a project is already approved, when you're just trying to pull the actual building permit to start construction.

Governor Newsom signed it September 29, 2026, as part of the same housing package that included rules on ADUs, factory-built housing, and mobile home parks. Like most new California laws, it takes effect January 1, 2027.

This is the paperwork and inspection stage that trips up a lot of homeowners, builders, and remodelers in Ventura County. You've got your approvals. Now you're stuck waiting on plan check, or an inspector sends you back for something that wasn't flagged the first three times.

What specifically changes?

• Fewer surprise field changes. Inspectors can't require changes that deviate from plans the agency already approved.

• A cap on resubmittals. Agencies can't send your plan check back for revisions an unlimited number of times.

• A real deadline with teeth. If an agency misses its legal deadline to act on a complete application, you can go to court for a writ of mandate to compel approval, instead of just waiting indefinitely.

• No more open-ended extensions. Agencies can't keep pushing review deadlines out forever.

What this means for Ventura County homeowners and buyers

If you've ever pulled a permit in Camarillo, Simi Valley, Moorpark, or elsewhere in the county and felt like the process dragged on with no end in sight, this law targets exactly that experience.

It matters for:

• Homeowners adding an ADU or doing a major remodel, who depend on predictable permit timelines to budget a project.

• Buyers eyeing a fixer-upper or a lot for new construction, where permit delays can quietly eat months of carrying costs.

• Investors and builders managing multiple projects across different cities, where inconsistent local permit timelines have been a real cost driver.

One caveat: the law is written around housing development projects, so it's worth confirming with your city how it applies to a single homeowner's remodel or ADU permit before you count on it.

What this means for sellers

Anything that makes new construction or additions move faster can add competing inventory over time. That's worth knowing if you're thinking about timing a sale around new supply coming online.

What to check before relying on this

The law takes effect January 1, 2027. If you have a project moving through permitting right now, ask your city's building department directly how AB 1621 will affect your specific application once it's in force.

FAQ

What is a "post-entitlement phase permit"?
It's the nondiscretionary permit needed to actually start construction after a project is already approved, such as a building, demolition, grading, or off-site construction permit.

Does AB 1621 stop cities from requiring building permits at all?
No. It doesn't remove the permit process. It limits how agencies can slow-walk or repeatedly send back an application once it's in that process.

What happens if a city misses its deadline under AB 1621?
The applicant can seek a writ of mandate from a court to compel approval, instead of the agency being able to extend the deadline indefinitely.

Does this apply to a homeowner's single ADU or remodel permit?
The law is aimed at housing development projects. Ask your city's building department how it applies to an individual homeowner permit.

When does AB 1621 take effect?
January 1, 2027.

Was this part of a larger housing law package?
Yes. AB 1621 was signed on September 29, 2026, alongside dozens of other housing bills, including laws on ADUs, factory-built housing, and mobile home parks.

A quick note from Steve

I'm not a contractor or an attorney, and this isn't permitting or legal advice. What I can help with is the real estate side: whether a project pencils out, what it could do for your home's value, or what to expect if you're buying a property with an in-progress or planned permit.

Want to talk through a specific project or property? Call or text 805-424-6226 or book a call.

Sources

• Governor Newsom signs housing legislation (official release, 9/29/2026)

• California Enacts Another Wave of 2026 Housing Bills (Brownstein)

Steve Hise & Tricia Garcia, Real Estate Toolbox at eXp Realty
Steve Hise CA DRE #01702055 | Tricia Garcia CA DRE #02032007