Will my property taxes be reassessed if I legalize my ADU under AB 2533?

Yes, but typically modestly. Once the ADU is legal, the County Assessor will add its assessed value to your property roll going forward — Casita Coalition (the bill's sponsor) characterizes typical post-amnesty reassessments as well below what owners fear. The bigger tax risk is the opposite scenario: if a code-enforcement complaint discovers the unpermitted unit before you legalize, the assessor can pursue a retroactive reassessment. AB 2533 lets you control the timing. Always confirm the specific dollar impact with a California-licensed CPA before applying.

If I ask my city's planning department about AB 2533, will they open a code-enforcement case against me?

No — and AB 2533 explicitly forbids it. The bill prohibits local agencies from penalizing applicants who come forward to legalize. The state mandates every California city/county to (1) publish public-facing legalization information and (2) provide a confidential third-party code inspection pathway. You can also have a licensed contractor do a private pre-inspection against the Health & Safety Code §17920.3 checklist before you ever submit anything. The Casita Coalition's misconception list explicitly debunks the "if I ask, they'll come after me" fear.

Can the city force me to demolish my unpermitted ADU?

Only if the unit is so dangerous nobody should be living in it under Health & Safety Code §17920.3 — severe structural failure, no feasible path to sanitation, located in a fault/landslide/liquefaction zone. For any unit that can be brought to minimum life-safety standards, AB 2533 forbids cities from denying the legalization permit. The choice between retrofit and demolition is yours, not the city's, except in those extreme cases.

Will my legalized ADU be subject to rent control or eviction protections?

It depends on your city. Local ordinances vary widely. In Oakland, for example, the Rent Adjustment Ordinance applies to ADUs built 10+ years before tenancy begins, and Just Cause Eviction applies regardless of age. Berkeley, San Francisco, Los Angeles, and Santa Monica also have rent-stabilization frameworks that may or may not cover newly legalized ADUs depending on construction date and ordinance specifics. AB 2533 itself does not affect rent-control coverage — that's purely a local-law question.

Do I have to disclose my unpermitted ADU to my insurance company while legalizing?

Yes — and this is one of the strongest reasons to use AB 2533 rather than continuing to hide the unit. Most California homeowner policies exclude damage to unpermitted structures, and carriers often deny related-loss claims (fire, flood, earthquake) on the main house if an undisclosed unpermitted unit contributed to the loss. Legalization restores normal coverage. Before applying, ask your broker how the carrier wants to handle the disclosure window — many insurers handle it as a routine endorsement once the Certificate of Occupancy issues.

What if my unpermitted ADU was built after January 1, 2020 — am I out of luck?

Under AB 2533 specifically, yes — the 2020 cutoff is a hard line in the state statute. But you may still have local options. Oakland's Planning Code Amnesty extends to units built/occupied before January 1, 2021 (one year more generous than the state floor). SB 13 (2019, Gov Code §17980.12) still requires every California city to delay code enforcement up to 5 years for ADUs with no health/safety issues — that's a parallel pathway. Confirm with your city before assuming you have to demolish or stay hidden.

Does AB 2533 protect me from having to bring the unit fully up to current building code?

Yes, in part. Cities can only require corrective work for items on the Health & Safety Code §17920.3 substandard checklist — egress, sanitation, structural safety, fire hazards, working utilities. They cannot require you to bring the unit as a whole up to current Title 24 energy code, ADA, or other modern requirements that didn't exist when it was built. Per the bill's sponsor: "Current building code only applies to work needed to bring units into safety compliance that may require a permit to complete, not to the unit as a whole." If a fix itself needs a permit (e.g., new electrical panel), that specific scope of work must meet current code.

Should I build a new ADU now and legalize it later under future amnesty?

No. The Casita Coalition (the bill's sponsor) explicitly warns against this strategy. AB 2533 was designed to address a pre-existing inventory of hidden housing — units built before January 1, 2020. Newly constructed unpermitted units built today won't get any equivalent future exemption. Building new today without a permit means you incur daily code-enforcement fines, retroactive impact fees, normal current-code retrofit costs, and insurance gaps without any of the AB 2533 protections.

AB 2533 Explained: California's ADU Amnesty Law (2026 Homeowner Guide)

What AB 2533 actually does

Assembly Bill 2533 was introduced by Assemblymember Juan Carrillo (D-Palmdale), sponsored by the Casita Coalition, signed by Governor Newsom on September 28, 2024, and took effect January 1, 2025. It amends California's Planning and Zoning Law (now codified in the §66313–66342 block of the Government Code after the SB 477 renumbering; the operative legalization section is Gov. Code §66332).

The bill does five things:

Extends the amnesty cutoff from January 1, 2018 to January 1, 2020 — three additional years of unpermitted ADU construction now qualify for the streamlined legalization pathway.
Adds JADUs (Junior ADUs) to the amnesty pathway. Prior law covered ADUs only.
Forbids cities from denying a legalization permit for code violations unless the unit qualifies as "substandard" under Health & Safety Code §17920.3.
Bans impact fees, connection charges, and capacity charges — except where new utility infrastructure is required to remediate a §17920.3 violation.
Requires every city and county to publish public-facing legalization information, a §17920.3 substandard- conditions checklist, and notice that the homeowner may obtain a confidential third-party code inspection from a licensed contractor before applying.

Put plainly: if your unpermitted ADU was built before January 1, 2020 and it isn't actively unsafe, the city has to take your application, cannot impose impact fees, cannot impose retroactive penalties, and cannot require you to bring the whole unit up to current code. It's the strongest legalization pathway California has ever offered.

How this differs from what came before

California has had ADU amnesty rules since 2018 — they just didn't work very well in practice. The prior pathway under SB 1226 (2018) and SB 13 (2019) gave local building officials discretion to apply codes in effect at the time of construction. Many cities chose to interpret that narrowly and effectively required full current-code retrofits, making legalization economically prohibitive for most owners.

AB 2533 narrows that discretion. Cities now must apply the §17920.3 standard, not their preferred reading of current code. The bill also explicitly extends SB 13's 5-year code-enforcement delay so owners have time to correct issues without daily fines piling up.

Casita Coalition's blog quotes former LA County zoning-enforcement officer Jonathan Pacheco Bell on the prior regime: "The permit process can be intimidating, expensive, and confusing — even worse if you're trying to legalize an ADU after the fact." AB 2533 was designed to fix exactly that.

Who qualifies — the eligibility rules

Three conditions, and any property type:

Construction cutoff: the ADU or JADU must have been constructed before January 1, 2020. This is a hard state-statute line. (Oakland's local amnesty extends to Jan 1, 2021, a year more generous than the state floor — see the city-by-city section below.)
Property type: any residential lot. Single-family, duplex, multifamily — the bill text imposes no restriction. All structural types qualify: detached backyard ADUs, garage conversions, basement/attic conversions, attached additions, and JADUs (≤500 sq ft within an existing single-family residence).
Not substandard under H&S §17920.3: the city can deny the permit only if the unit meets the legal definition of "substandard." That's a fairly specific list (see below) — not "the unit doesn't meet current code." Most unpermitted ADUs we've seen discussed publicly can clear this bar with $10,000–$50,000 of corrective work.

A few practical exclusions surfaced in city implementations: San Diego's Information Bulletin 242 specifically excludes units that sit in fault, landslide, or liquefaction zones; units created by excavating under existing floor space; units built with non-Code materials; units sitting on a public or private easement; and units attached to an existing apartment building or commercial structure. Coastal Zone parcels also require separate Coastal Development Permit review under the Coastal Act, even with AB 2533.

The §17920.3 checklist — what cities can still require

The single most important phrase in AB 2533 is "substandard under §17920.3." That section of the Health & Safety Code defines what actually counts as a dangerous unit. Cities can require you to fix anything on this list; they cannot require anything beyond it.

Sanitation: missing or improper water closet, lavatory, tub or shower, kitchen sink; no hot/cold running water; inadequate heating; missing ventilation; insufficient natural light; rooms below minimum dimensions; visible mold; insect or rodent infestation; missing sewage connection.
Structural hazards: deteriorated foundation; undersized floor, wall, or roof supports; leaning or buckling walls; sagging roof; bulging chimney; inadequate horizontal-force resistance.
Wiring, plumbing, and mechanical: any of the above that doesn't conform to laws in effect at the time of installation and isn't in current good safe working condition.
Weather protection: crumbling plaster, broken windows or doors, defective roof or wall coverings.
Fire hazards: combustible accumulations, inadequate exits, missing required fire-resistive construction.
Occupancy mismatch: the building is being used for sleeping, cooking, or dining when it was never designed for it.

Per the Casita Coalition: "Current building code only applies to work needed to bring units into safety compliance that may require a permit to complete, not to the unit as a whole." If a fix itself requires a permit — say, a new electrical panel to meet GFCI requirements — that specific scope of work must meet current code. The rest of the unit doesn't.

The application process, step by step

Process varies slightly by city, but the shape is consistent across every California jurisdiction we surveyed:

Confidential pre-inspection (optional, strongly recommended). Hire a licensed contractor — separate from the city — to walk the unit against the §17920.3 checklist. Cost: $500–$1,500. Outcome: a written list of what you'll need to fix. Several cities (Hayward, Orange County) explicitly support this. Importantly: this does not trigger any city action against you.
Assemble documentation. Two categories are essential. (1) Proof of pre-2020 construction — County Assessor records, escrow disclosures, prior building or planning records, utility bills, dated photos (Google Earth historical imagery is commonly accepted), notarized letters from prior owners or tenants, contractor bills. (2) As-built plans drawn by an architect, designer, or engineer showing site plan, floor plan, elevations, and the locations of cooking appliances, the toilet, water heater, heating element, smoke and CO alarms, egress windows, and GFCI outlets. Architect cost: $3,000–$8,000.
Submit the legalization permit application. Through the city's online portal in most jurisdictions (Accela in Oakland, ProjectDox in San Diego, the LADBS portal in Los Angeles). The application notes "AB 2533 legalization." Standard permit and plan-check fees apply (typically $500–$1,500 in total); impact fees, connection fees, and capacity fees are waived under the bill.
City review against §17920.3. The building department reviews your plans and (typically) sends an inspector to the unit. They produce a list of corrective items based on the §17920.3 checklist, not current Title 24 / ADA / general code.
Corrective work. You complete the required fixes. Common items: egress window enlargement ($500–$3,000), GFCI outlets ($150–$400), smoke/CO detectors ($100–$300), electrical panel upgrade if existing is inadequate ($1,500–$3,000), ventilation fixes ($500–$2,500). GreatBuildz's published range for total retrofit work is $10,000–$50,000; the Casita Coalition guidebook notes some units are so deteriorated that demolish-and-rebuild makes more financial sense than retrofit.
Final inspection and Certificate of Occupancy. Once corrective work passes inspection, the unit receives a Certificate of Occupancy (or Certificate of Compliance). It's now a legal ADU/JADU — fully insurable, rentable, financeable, and appraisable as a permitted unit.

Realistic end-to-end timeline: 2–6 months from complete application to final approval, per LADU and GreatBuildz reporting. The biggest bottleneck is producing the as-built plans (3– 8 weeks for an architect). Cities can take longer if the unit triggers a substantial §17920.3 fix list.

City-by-city implementation in California

AB 2533 is self-executing — every California city and county must accept applications under it as of Jan 1, 2025, even where no local ordinance has been passed. Here's what we've observed across the major metros (we maintain bundled city pages with current data; links below):

Oakland runs the most homeowner-friendly implementation we found. Three parallel paths: (1) Planning Code Amnesty for units built/occupied before Jan 1, 2021 — a year more generous than the state floor — with applications open until Jan 1, 2030. (2) A 5-year Building Code Enforcement Delay running through Jan 1, 2035. (3) The standard AB 2533 state program for units built before Jan 1, 2020. Excludes properties in the S-9 Fire Safety Protection Zone. See the Oakland ADU guide.
Berkeley runs an active 2025–2028 Pilot Amnesty Program with a flat $590 application fee and a two-path structure (Certificate of Occupancy for full code compliance, Housing Certificate of Compliance for life-safety minimum). Includes an optional 5-year code-enforcement delay. See the Berkeley ADU guide.
Los Angeles runs AB 2533 alongside its pre- existing Unpermitted Dwelling Unit (UDU) Ordinance (Ord. 184,907, effective 2017), which is a parallel local pathway that requires legalized units to provide at least one low/moderate-income unit per UDU. LADBS accepts AB 2533 applications without the UDU affordability covenant. See the LA ADU guide.
San Diegohas formalized AB 2533 in Information Bulletin 242 (last updated May 2026). Water and sewer capacity fees are explicitly waived. C&D recycling deposit waived. Coastal Zone parcels still need a separate Coastal Development Permit. See the San Diego ADU guide.
Santa Clara County (and San Jose) publish a three-component program: a zoning reprieve, the 5-year enforcement delay, and AB 2533 legalization. San Jose also runs informal "ADU Tuesdays" walk-in consultations. See the San Jose ADU guide.
San Francisco integrates AB 2533 with its existing Accessory Building Establishment (ABE) program under Ordinance 22-15. SF Planning waives building-permit fees for legalizing qualifying pre-2020 units. See the SF ADU guide.
Other early adopters with documented AB 2533 implementations: Orange County (unincorporated, "Safe ADU/JADU Legalization"), Santa Cruz County (with a mandatory contractor- completed substandard checklist), Riverside ("Safety-First Amnesty Program"), El Cerrito, Walnut Creek, San Luis Obispo, Hayward (flat $570 fee + confidential consultations), Foster City, Milpitas.

If your city hasn't yet posted the required public information or substandard checklist, you can still apply — the state law is binding regardless of local rollout pace. Cite Gov. Code §66332 in your application and apply via the standard residential permit pathway with "AB 2533 legalization" noted in the scope of work.

What it costs vs. what you avoid

Total cost of using AB 2533 for a typical pre-2020 unpermitted ADU in 2026:

City permit application fees: $570–$800 (Berkeley $590, Hayward $570 typical)
Architect for as-built plans: $3,000–$8,000
Optional contractor pre-inspection: $500–$1,500
Structural engineer (if needed): $2,000–$5,000
Retrofit work to clear §17920.3 items: $10,000–$50,000 typical (Casita Coalition's wider range is $20,000–$200,000+ for severely deteriorated units)

Total all-in: most owners land at $15,000–$60,000 depending on how much corrective work the unit needs.

What you avoid by participating instead of staying hidden or being caught:

Daily code-enforcement fines. California jurisdictions assess unpermitted-construction fines in the $500–$5,000 per day range depending on local ordinance. A year-long enforcement case can rack up six figures.
Retroactive impact fees and connection charges. $5,000–$25,000 in most CA cities for ADUs above 750 sq ft — fully waived under AB 2533.
Forced demolition orders. Possible under enforcement; effectively impossible under AB 2533 unless the unit is so dangerous nobody should be living in it.
Retroactive property tax reassessment. Assessors can pursue back-assessments when a complaint surfaces an unpermitted unit. Legalization brings the reassessment forward on your timeline at the legalized value (typically less punitive than a discovery scenario).
Insurance denial. Most California homeowner policies exclude damage to unpermitted structures; carriers can deny related-loss claims (fire, flood, earthquake) on the main house if an undisclosed unpermitted unit contributed. Legalization restores normal coverage.
Property-sale discounts. Permitted ADUs add 20– 30% more property value vs. their unpermitted equivalent (GreatBuildz 2026). On a typical California single-family home with an ADU, that's $100,000+ in transaction-time appraisal uplift.

For most owners, the math is straightforward: a $20,000–$40,000 legalization investment unlocks $100,000+ in appraised value, restores insurance coverage, eliminates daily-fine risk, and lets you legally collect rent. Outside of severely deteriorated units, the case for applying is overwhelming.

The five blockers — and why none of them should stop you

Across Reddit and Facebook ADU communities, five fears keep owners from coming forward. We address each in the FAQ below, but in summary:

Property tax reassessment. Real, but typically modest — and the bigger risk is the opposite scenario where a complaint forces it.
Code enforcement risk from asking. AB 2533 explicitly forbids cities from penalizing applicants. Confidential pre-inspection is available.
Forced demolition. Only if the unit is truly unsafe under §17920.3 — for any retrofittable unit, the city must grant the permit.
Rent control on the legalized unit. Depends on your city's ordinance; AB 2533 doesn't change local rent rules either way.
Insurance disclosure. Disclosing during legalization is the right move — most policies exclude unpermitted structures anyway, and carriers handle the post-CofO endorsement as routine.

Bottom line

AB 2533 is the most generous ADU legalization framework California has ever offered. If your unpermitted ADU or JADU was built before January 1, 2020 and isn't catastrophically unsafe, the city is statutorily required to take your application, waive impact fees and retroactive penalties, and let you stay on the unit as-is for anything that isn't on the §17920.3 checklist. The bill's sponsor — the Casita Coalition — explicitly warns owners not to wait for a future amnesty for newly-built unpermitted units; AB 2533 was designed to address a pre-existing inventory, and Sacramento is unlikely to repeat the gift.

Three concrete next steps for any owner sitting on an unpermitted unit:

Read your city's AB 2533 implementation page (linked in the sources below) or our matching city ADU guide if we cover your metro.
Hire a licensed contractor for a confidential pre-inspection against the §17920.3 checklist. $500–$1,500, no city involvement, no enforcement risk.
If the unit is retrofittable, engage an architect for as-built plans and submit a legalization permit citing AB 2533. Standard permit fees apply; impact fees and penalties do not.

Need to estimate the retrofit cost? Run the ADU cost calculator with the "garage conversion" or "JADU" tier (mid-finish) and add a 15–20% contingency for code-correction items. Want help finding a builder who has done this before in your city? See the vetted ADU builder directory.

AB 2533: California's ADU amnesty law, explained