Florida Lets You Skip City Plan Review. California's AB 253 Is a Cautious First Step.
ADU Pilot Team
ADU Pilot Team
AB 253 gave California homeowners a new right: if your building department takes longer than 30 business days to review your plans, you can hire your own licensed reviewer. The city then has 10 business days to approve or reject — silence means your permit is deemed approved. The law has been in effect since October 10, 2025. As of April 2026, no public record exists of anyone using it. This guide covers the precise trigger, the step-by-step process, the cost, and the limitations that explain why adoption has been slow. For the broader ADU permitting landscape, see our California ADU laws 2026 guide. For the completeness-review shot clock that precedes AB 253 in the permit timeline, see our SB 543 analysis.
Bottom Line
- AB 253 is an urgency statute signed by Governor Newsom on October 10, 2025, effective immediately — not January 1, 2026. Most secondary sources get this wrong. [1][2]
- The trigger is specific: 30 business days after your application is deemed complete and fees are paid, if the city has not completed plan check on all applicable disciplines. You then have 5 business days to notify the city of your intent to hire a private reviewer. [3]
- You pay the private plan checker ($3,000–$10,000 estimated for an ADU project) on top of normal city permit fees. You also sign an indemnification agreeing to hold the city harmless for any issues arising from construction based on the privately reviewed plans. [2][4]
The Law Most People Think Took Effect in January
AB 253, the California Residential Private Permitting Review Act, passed the Assembly 72-0 and the Senate unanimously. The Assembly concurred on Senate amendments 77-0. Zero legislators voted against it. [5]
Governor Newsom signed it as an urgency statute under Chapter 487, Statutes of 2025. Urgency statutes take effect on the date of signature, not the following January 1. AB 253 has been enforceable since October 10, 2025 — six months before this article's publication date. [1]
The law adds Health and Safety Code §17960.3, which establishes the core private plan check mechanism. It also amends §17951 (requiring cities to publish permit fee schedules online) and §17960.1 (the existing framework for government-initiated delegation to private reviewers). §17960.3 sunsets on January 1, 2036. [1][3]
The author is Assemblymember Chris Ward (D-San Diego). The sponsor is California YIMBY. CALBO (the California Building Officials association) formally opposed the bill. [5][6]
How It Works: The Seven-Step Sequence
Step 1: Your application is deemed complete
The clock starts when the city determines your building permit application is complete and you have paid all required fees. Under SB 543 (effective January 1, 2026), the city must make this completeness determination within 15 business days for ADU applications, or the application is automatically deemed complete. [3][7]
Step 2: 30 business days pass without a plan check decision
If the city either (a) tells you at the time of completeness determination that plan review will take longer than 30 business days, or (b) simply has not completed the review across all applicable disciplines after 30 business days, the trigger is met. [3]
"All applicable disciplines" means structural, mechanical, electrical, energy, plumbing, gas systems, accessibility, life safety, fire suppression, fire alarm, hazardous materials, and smoke control — whichever apply to your project. If even one discipline remains unreviewed after 30 business days, the trigger is met for that discipline. [4]
Step 3: You notify the city within 5 business days
Once the trigger is met, you have 5 business days to submit written notice to the city that you intend to hire a private plan checker. The notice must follow the city's prescribed form — San Diego, for example, uses Form DS-253A. [3][4]
Step 4: You hire a qualified private plan checker
The reviewer must hold both:
- A California PE (Professional Engineer) license or California Architect license, and
- An ICC (International Code Council) Certified Residential Plans Examiner credential or an IAPMO (International Association of Plumbing and Mechanical Officials) Certified Plans Examiner credential [4]
The reviewer cannot have any financial interest in the building permit or the design documents. You pay them directly. No state registry of AB 253-qualified reviewers exists as of April 2026. [4]
Step 5: The private reviewer submits a report
The reviewer examines the plans for compliance with the State Housing Law and applicable local building code amendments. The submission includes stamped/signed plans and a sworn affidavit (San Diego uses Form DS-253B) confirming compliance. [4]
San Diego's implementation requires that if you invoke AB 253, the private reviewer must cover all applicable disciplines — you cannot cherry-pick some disciplines for private review and leave others to the city. [4]
Step 6: The city has 10 business days to respond
The city must, within 10 business days of receiving the private reviewer's report, either:
- Issue the building permit, or
- Provide written notice that the plans do not comply, specifying exactly what requirements are unmet [3]
If the city issues corrections, you revise and resubmit. The city then gets another 10 business days to review the resubmission. [4]
Step 7: Silence = deemed approved
If the city neither issues the permit nor provides a written non-compliance notice within the 10 business days, and the private reviewer's affidavit confirms compliance, the building permit is deemed approved by operation of law. [3]
A critical caveat: "deemed approved" is a legal status, not a physical document. You will not automatically receive a building permit card to post at your job site. If the city remains silent and you believe the permit is deemed approved, you may need to demand the city issue the permit in writing, file a complaint with HCD, or retain an attorney to enforce the deemed-approval provision. SB 543's parallel "deemed approved" mechanism for the 60-day entitlement clock faces the same practical gap. No AB 253 deemed-approval has been tested in court or through HCD enforcement as of April 2026. Treat this provision as a powerful legal lever, not a self-executing permit.
What AB 253 Does Not Do
The law's boundaries are as important as its provisions:
No inspection bypass. AB 253 covers plan review only. All field inspections during construction are still performed by the city's building department. San Diego's guidance explicitly warns that because the city did not conduct the detailed plan review, inspectors may identify issues during construction that would have been caught earlier in a city-led plan check. [4]
No fee waiver. You pay the city's permit fees in full, plus the private reviewer's fees. AB 253 requires that city fees not exceed the "reasonable amount necessary to administer, process, or enforce" the permit, but does not eliminate them. [2]
No coverage for discretionary permits. AB 253 applies to ministerial building permits for residential projects of 1–10 units, not exceeding 40 feet in height. It does not apply to Coastal Development Permits, conditional use permits, or any other discretionary land-use entitlement. In the Coastal Zone, the building permit plan check stage (post-CDP) could use AB 253, but the CDP process itself cannot. [2][3]
Indemnification required. The applicant must indemnify the local government against liability for property damage or personal injury arising from construction based on privately reviewed plans. The city and its employees are expressly shielded from liability under §17960.3. [2]
How AB 253 and SB 543 Work Together
For ADU builders, these two laws cover different segments of the same permit timeline:
| Stage | Law | Clock | Consequence of Government Inaction |
|---|---|---|---|
| Completeness review | SB 543 | 15 business days | Application deemed complete [7] |
| Planning/entitlement | Existing ADU law | 60 calendar days | Permit deemed approved [7] |
| Building plan check | AB 253 | 30 business days | Applicant can hire private reviewer |
| City review of private report | AB 253 | 10 business days | Permit deemed approved |
SB 543 eliminates the front-end stall tactic: cities can no longer hold an application in "incomplete" limbo indefinitely. AB 253 eliminates the mid-stage stall: once plans are in for review, the city cannot let them sit in a queue for months without consequence. For the full SB 543 analysis, including the prohibition on raising new objections in a second review cycle, see our SB 543 enforcement guide.
The gap AB 253 does not close is the inspection stage. After the building permit issues, construction inspections remain entirely under city control, with no private alternative and no statutory shot clock.
One additional interaction: if you use pre-approved ADU plans under AB 434, plan check should be faster (San Jose offers same-day approval for qualifying pre-approved plans). AB 253 is less likely to be triggered. But if a pre-approved plan stalls in plan check despite pre-approval status — perhaps because site-specific conditions require additional review — AB 253 still applies. For more on the pre-approved plan mandate, see our AB 1332 guide.
Why Building Officials Oppose It
CALBO's formal opposition raised three arguments worth understanding: [6]
Safety scope. AB 253 extends a model originally designed for small ADU pre-approved plans (AB 1332, 2023) to residential projects up to 10 units and 40 feet tall. CALBO argues that multi-story, multi-unit residential projects involve fire suppression, egress, and smoke control systems that are substantially more complex than a backyard ADU, and that applicant-selected private reviewers lack the institutional knowledge and accountability that city plan check staff accumulate over thousands of reviews.
Selection bias. Under the prior framework (§17960.1), the city chose which private reviewer to contract. Under AB 253, the applicant chooses. CALBO contends this creates a structural incentive for reviewers to approve plans quickly to win repeat business, without the counterbalancing pressure of government oversight.
Paradoxical delay. CALBO suggests that if a private reviewer submits a report and the city identifies errors during its 10-day review, the correction-resubmission cycle could take longer than if the city had completed the plan check itself — especially for complex projects where the city reviewer's institutional familiarity with local amendments would have caught issues earlier.
These are not trivial objections. The 72-0 Assembly vote suggests the legislature weighed them and concluded the status quo — permit queues measured in months — was a greater problem.
What Cities Might Do in Response
CALBO's objections also hint at defensive strategies cities could deploy without formally violating AB 253:
Partial review at day 29. A city could issue a minimal comment on one discipline just before the 30-business-day deadline — even a single note like "structural review in progress, comments forthcoming" — to argue the trigger has not been met. Whether this constitutes "completing" the review on that discipline is untested.
Aggressive corrections during the 10-day window. After receiving the private reviewer's report, the city could issue an exhaustive non-compliance notice on local code amendments the private reviewer may have missed, forcing a resubmission cycle that adds weeks.
Stricter inspections. City inspectors encountering plans they did not review may apply heightened scrutiny during construction. This is not retaliation in a legal sense — inspectors have broad discretion over field compliance — but it is a foreseeable consequence. Contractors experienced with a given jurisdiction's inspectors understand this dynamic intuitively; homeowners building their first ADU may not.
None of these responses are illegal. They are the predictable institutional friction of a system adjusting to a new constraint. Homeowners considering AB 253 should weigh these risks alongside the time savings.
The Florida Benchmark
Florida Statute §553.791 is the most mature private plan review law in the United States. It reveals how much further California could eventually go: [8]
| Feature | Florida §553.791 | California AB 253 |
|---|---|---|
| Project types | All buildings (commercial + residential) | Residential only, 1–10 units, ≤40 ft |
| Trigger | None — applicant can choose private review at any time | Must wait 30 business days after deemed complete |
| Scope | Plan review and field inspections | Plan review only; inspections remain with city |
| Fee structure | City fees are reduced when private review is used | No reduction; applicant pays both city and private fees |
| City response | Private review has same legal force as city review | City retains 10-day veto window |
| Insurance | Private reviewer must carry $1M/$2M professional liability | Not specified in statute |
Florida's law has been in place for decades and is widely used — private providers handle a significant share of residential permits in many Florida counties. The system works because private reviewers carry mandatory $1M/$2M professional liability insurance, city fees are reduced (not doubled), and private review carries the same legal force as city review with no 10-day veto window. Florida also includes field inspections, meaning a homeowner can bypass the city building department for the entire permit-to-certificate-of-occupancy pipeline. [8]
AB 253 is narrower on every dimension. The legislature's own committee analysis cited Florida, Tennessee, and Texas as models but chose a more conservative path: residential only, trigger-based rather than elective, plan check only without inspections, and a city veto window that Florida does not have. [5]
The gap between the two laws measures how much California still trusts local building departments as the default, and how much further deregulation could go if AB 253's cautious model proves safe. If AB 253 reaches its 2036 sunset date without safety incidents, the logical next step is expanding scope to include inspections and removing the 30-day trigger — moving California closer to the Florida model.
In the meantime, AB 253 functions as a negotiating tool as much as a procedural one. The threat of private plan check — and the "deemed approved" consequence of silence — may accelerate city review even if no homeowner formally invokes it. The law changes the default from "the applicant waits" to "the city must act."
What It Costs
No standardized AB 253 pricing exists yet. Based on comparable private plan check services in California: [9]
| Cost component | Estimated range |
|---|---|
| City building permit fees (unchanged) | $5,000–$15,000 for a typical ADU |
| Private plan checker (all disciplines) | $3,000–$10,000 |
| Total with AB 253 | $8,000–$25,000 |
| Total without AB 253 | $5,000–$15,000 |
The premium is real: $3,000–$10,000 for the private review, with no city fee offset. Under San Diego's implementation, the private reviewer must cover all applicable disciplines even if the city already reviewed some of them — you are paying to re-review work the city may have already completed. For a simple ADU with 5–6 applicable disciplines, this is manageable. For a project approaching the 10-unit ceiling, the cost scales accordingly. [4]
This makes AB 253 a tool of last resort for projects where the time cost of delay exceeds the fee premium — a calculation that favors investors carrying construction loans (where every month of delay costs $1,500–$4,000 in interest) over homeowners building on savings.
Three Scenarios
Scenario 1: City is simply backlogged. Your ADU application was deemed complete 35 business days ago. No plan check comments have been issued on any discipline. You notify the city, hire a private PE with ICC certification. The reviewer completes the review in 2 weeks. The city issues the permit within 10 business days of receiving the report. Total time saved: potentially 2–4 months.
Scenario 2: City issued partial comments. The structural and plumbing disciplines were reviewed, but electrical, energy, and fire remain untouched after 30 business days. The trigger is met because plan check is not complete across all applicable disciplines. You invoke AB 253. Under San Diego's implementation, the private reviewer must then cover all applicable disciplines — including the ones the city already reviewed. You cannot cherry-pick. The city has 10 business days to respond to the complete private report.
Scenario 3: City uses "death by corrections." The city completed an initial review within 30 business days and issued extensive corrections. You revise and resubmit. The second review stalls. If §17960.3's 30-business-day trigger applies to resubmission review cycles (a reasonable reading, since each plan check cycle is a distinct review, but not explicitly confirmed in the statute text), you can invoke the private review pathway again on the resubmission. [3] This scenario also benefits from SB 543's prohibition on raising new objections not identified in the initial review — the city cannot keep inventing new issues across successive cycles. The combination of SB 543 (no new objections) and AB 253 (time limit on review) is the strongest anti-delay toolkit currently available.
Who Has Used It
As of April 14, 2026: no one, publicly. The law requires cities to report AB 253 usage data to HCD starting April 1, 2027. [3] Until then, usage is invisible.
San Diego's AB 253 guidance page includes a candid disclosure: "At the time of publication, review timeframes for eligible project types do not exceed 30 business days." [4] In other words, San Diego's current performance does not trigger AB 253. This may be the law's most important effect: the mere existence of a private review escape valve incentivizes cities to keep plan check times under 30 business days.
The cities where AB 253 is most likely to matter are those with chronic backlogs: parts of Los Angeles, some Bay Area jurisdictions, and smaller cities with limited plan check staff. If your project is in a jurisdiction where plan check regularly exceeds two months, AB 253 is already available to you.
References
[1] AB 253, Chapter 487, Statutes of 2025. California Health and Safety Code §17960.3. Bill status: https://leginfo.legislature.ca.gov/faces/billStatusClient.xhtml?bill_id=202520260AB253
[2] Burke, Williams & Sorensen LLP, "New 2026 Laws Impacting Building Permits for New Housing," 2025. https://www.bwslaw.com/insights/new-2026-laws-impacting-building-permits-for-new-housing/
[3] AB 253 bill text (enrolled version). https://legiscan.com/CA/text/AB253/id/3262113
[4] City of San Diego, Development Services Department, "AB 253 — California Residential Private Permitting Review Act." https://www.sandiego.gov/development-services/news-programs/ab253
[5] California YIMBY, "AB 253 — Residential Permitting Reform." https://cayimby.org/legislation/ab-253/ ; Assembly Housing and Community Development Committee analysis. https://ahcd.assembly.ca.gov/system/files/2025-03/ab253_01-15-2025_ward_housing-and-community-development_abpca.pdf
[6] CALBO (California Building Officials), "AB 253 — Oppose." https://www.calbo.org/post/ab-253-ward-quirk-silva ; Opposition letter: https://www.calbo.org/sites/main/files/file-attachments/ab_253_-_oppose.pdf
[7] SB 543, effective January 1, 2026. For full analysis, see our SB 543 enforcement guide and SB 543 impact analysis.
[8] Florida Statute §553.791, "Alternative Plans Review and Inspection." https://www.leg.state.fl.us/Statutes/index.cfm?App_mode=Display_Statute&URL=0500-0599/0553/Sections/0553.791.html
[9] Private plan check cost estimates based on ICC-certified reviewer market rates (ZipRecruiter California data, 2026) and comparable private plan check services. Actual costs vary by project scope and jurisdiction. City permit fee ranges from San Jose and San Diego published fee schedules.
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