ADU Permits in California

California’s ADU law is not a suggestion that cities get to quietly ignore. The state sets a floor: ministerial approval, a hard deadline, size protections no local ordinance can shrink. What a city does above that floor, how fast its plan checkers actually move, whether its own ordinance is even fully legal yet, is a different question entirely.

I work across California, not just one city, and the gap between what the law promises and what actually happens at the counter is the most useful thing I can tell you before you start.

What Changed for California ADU Permits in 2026

Four bills, AB 462, AB 1154, SB 9, and SB 543, were all signed by Governor Newsom in October 2025, and they reshape ADU permitting starting January 1, 2026 (AB 462 took effect immediately as an urgency measure). If you’re reading an older ADU guide right now, even one from earlier in 2025, some of what it tells you is already out of date.

SB 543 does the most structural work. It sets a firm 15-business-day deadline for a permitting agency to tell you whether your application is complete, which matters because the state’s 60-day ministerial clock can’t really start running until that happens. It also standardizes ADU and JADU size measurement to interior livable space statewide, and clarifies fee exemptions: no impact fees under 750 square feet, no school fees under 500 square feet, and no new utility connection fee for an attached ADU built inside an existing structure’s walls. I pulled these directly from the bill text on the Legislature’s own site, not a summary, because fee rules are exactly the kind of thing that gets paraphrased loosely elsewhere.

AB 1154 narrows the JADU owner-occupancy requirement so it only applies when the JADU shares a bathroom with the main house. Share sanitation and you still need to live on-site; keep the JADU’s bathroom separate and that requirement disappears. AB 462 speeds up Coastal Development Permits, requiring agencies with a certified coastal program to decide within 60 days, running at the same time as the ministerial review instead of stacked after it.

Then there’s SB 9, and here’s a genuine gotcha. This is not the famous 2021 SB 9 that let homeowners split lots and build duplexes. The legislature reused the bill number in a new session for a completely different law, one that gives HCD real teeth against cities that drag their feet on ADU ordinances. If a city doesn’t submit its ADU ordinance to HCD within 60 days of adopting it, or doesn’t respond to HCD’s compliance findings within 30 days, that ordinance becomes void and the state’s own standards apply directly. I’ve seen a homeowner cite the wrong SB 9 in a planning meeting, and it did not go well for the argument they were trying to make.

What State Law Guarantees You

Strip out the local variation and here’s what actually cannot be taken away from you anywhere in California.

Ministerial, by-right approval is the baseline. No hearing, no neighbor objection process, no planning commission vote, as long as your project meets objective standards. That alone is the biggest structural advantage California ADU applicants have over most of the rest of the country.

The timeline is a legal deadline, not a target. Fifteen business days to confirm your application is complete, 60 days total from that point to an approval or denial. Miss that window and the application is deemed approved by operation of law, under Government Code Section 66317. Size is protected too: the state requires cities to allow at least an 800-square-foot detached ADU regardless of what local zoning would otherwise permit, and that minimum is now defined in interior livable space, not gross footprint.

Fees have real limits. Impact fees are waived entirely under 750 square feet of interior livable space for a standalone ADU, or 500 square feet for a JADU. School fees follow that same 500-square-foot line. And owner-occupancy, the requirement that trips up more homeowners than almost anything else, is never allowed for a standalone ADU, full stop.

Area	State mandate	What cities still control
Approval process	Ministerial, by-right; no hearing or discretionary vote allowed	Which department handles intake and how well-staffed their queue is
Review deadline	15 business days to confirm completeness, 60 days total to approve or deny	How fast corrections get rechecked once resubmitted
Size minimum	Must allow at least an 800 sq ft detached ADU regardless of local zoning	Maximum size above that floor, height limits, setbacks
Impact fees	Waived under 750 sq ft (ADU) or 500 sq ft (JADU) of interior livable space	Fee amounts above that threshold, and how fees are calculated
Owner-occupancy	Never required for a standalone ADU; required for a JADU only if it shares a bathroom with the main house	Nothing, this one is fully preempted
Design review	Objective standards only, no subjective aesthetic review for a compliant project	Coastal zone, hillside, and historic district overlays that stack extra review on top

Source: California Government Code Section 66317, SB 543 (2025), and AB 1154 (2025)

Phase	Legal deadline	What actually happens
Completeness review	15 business days (about 3 weeks)	Mostly on time; this deadline is new for 2026 and cities are still adjusting their intake process
Full ministerial decision	60 days from a complete application	Standard-plan projects often clear in 4 to 8 weeks; a custom design with a correction round commonly runs 8 to 16 weeks
Coastal Development Permit (if applicable)	60 days, run concurrently with the ministerial review under AB 462	Adds real time on top regardless, since it’s a separate approval most homeowners don’t expect
Deemed approved (missed deadline)	Automatic approval the day after the 60-day clock expires	Rarely invoked; most homeowners either don’t know the remedy exists or don’t want to fight the department that will be inspecting their build

Source: Government Code Section 66317 and ADU Wizard’s city permit pages

Notice what those numbers mean together. The legal ceiling on a standard ADU is roughly 75 days from a complete application, fifteen plus sixty, but that’s the outer limit, not the promise. A pre-approved Standard Plan project routinely beats it. A custom design that needs a correction round routinely blows past it, and honestly, how a correction round is supposed to interact with the 60-day clock is one of the more disputed parts of how cities apply the law in practice.

Where Cities Still Slow You Down

Here’s the honest version, because I’d rather you hear it from me than find out mid-project.

The state sets a floor, not a ceiling, and the distance between a good city and a slow one is enormous. Compare the cities I track closely: Los Angeles runs four to sixteen weeks depending on plan type, Riverside can clear in as little as one week with its Permit-Ready plans or stretch to twelve for a custom design, San Jose has reported cases running anywhere from three to twenty-six weeks, Long Beach can hit same-day approval with a Pre-Approved plan, and Berkeley typically lands around eight to twelve weeks. Same state law, wildly different real-world outcomes.

That said, some of that gap is legitimate: discretionary overlays the state doesn’t preempt. Coastal zones, hillside ordinances, and historic districts all add review layers on top of the ministerial process, not instead of it. Some of it is cities running local ordinances that haven’t actually been reconciled with current state law yet, which is exactly what HCD’s compliance process exists to catch.

I mentioned Los Angeles’s own situation on that city’s page, and it isn’t the only one. Check HCD’s enforcement letters dashboard if you want to see whether your city has an open finding before you assume every local rule you’ve been told about is actually enforceable.

Permit Rules by City in California

If you’re building in a city I track in detail, the local page has the real fee ranges, the specific department, and the local quirks that the state guarantees above don’t cover. Los Angeles, Riverside, San Jose, Long Beach, and Berkeley each have their own breakdown below, and if your city isn’t listed yet, the guarantees on this page are still your floor no matter where in California you’re building.

Frequently Asked Questions

Does California really require cities to approve ADU permits within 60 days?

Yes, under Government Code Section 66317, once your application is deemed complete. Cities also now have only 15 business days to tell you whether it’s complete in the first place, a new requirement from SB 543 starting January 1, 2026.

What happens if my city misses the 60-day deadline?

Your application is deemed approved by operation of law. In practice, I haven’t seen a homeowner actually invoke this remedy against their own building department, but the deadline still puts real pressure on cities to keep moving.

Do I need to live on my property to build an ADU in California?

No, standalone ADUs never carry an owner-occupancy requirement anywhere in the state. A JADU only requires it if the JADU shares a bathroom with the main house, a rule that changed under AB 1154 starting in 2026.

Are ADU impact fees really waived in California?

Yes, for ADUs under 750 square feet of interior livable space, or JADUs under 500 square feet. Above that size, cities can charge fees proportionate to the ADU’s size relative to the primary home.

Is the 2025 SB 9 the same law that let homeowners split lots and build duplexes?

No, and this trips people up constantly. That was the 2021 SB 9. The 2025 SB 9 is a different bill entirely, about HCD’s authority to void noncompliant local ADU ordinances; the legislature just reused the bill number in a new session.

If you’re pricing out an ADU rather than just permitting one, our California ADU cost breakdown has the fuller build numbers, and our Data Hub is the better source if you want current figures instead of one article’s snapshot. The permits pillar covers what changes if you’re comparing California against another state entirely.