Senate Bills

ADU Cities tracks the state laws that make ADUs possible. Every unit we design and build exists because Sacramento rewrote the rules — over the last decade, a run of California Senate bills turned the accessory dwelling unit from something most cities could block into something they must approve, ministerially, on a deadline, under statewide standards. These are the Senate bills that did it, in order.

One honest note on the calendar: no ADU Senate bills were chaptered in 2014 or 2015. The modern era starts with SB 1069 in 2016.

Taking Effect January 1, 2027

Two of the newest bills on this page are signed but not yet in force — both land on January 1, 2027. SB 1117 ends the fee cliff: for your first two ADUs, impact fees are charged only on the living area above 750 square feet. SB 1196 attacks the other end of the job — the state utilities commission must set firm deadlines for ADU utility hookups, with penalties when utilities miss them. Both are detailed in the list below.

SB 1069 (2016) — The Bill That Started It All

Author: Sen. Bob Wieckowski. The foundational reform. Cities must approve code-compliant ADUs ministerially — no discretionary hearings, no neighborhood votes — and the bill put the first real limits on parking mandates and utility connection fees. It is the reason ADU permits went from a rarity to a by-right process.

SB 229 (2017) — The Cleanup

Author: Sen. Bob Wieckowski. A year of clarifications: replacement parking can sit in any configuration when a garage comes down, sizing rules were cleaned up, and special districts were barred from treating an ADU as a brand-new home when calculating water and sewer connection charges.

SB 1226 (2018) — Which Code Applies

Author: Sen. Bob Wieckowski. A quiet deal-saver for conversions. When you convert existing space into an ADU, the building standards that apply are the ones in effect when the structure was originally built — not today's code — so a legal 1980s garage isn't judged by 2018 rules.

SB 13 (2019) — Fees and Lot Size

Author: Sen. Bob Wieckowski. The fee bill. No impact fees at all on ADUs under 750 square feet, proportional caps above that, no minimum lot size for an ADU anywhere in California, and a five-year ban on owner-occupancy requirements (later made permanent by AB 976 in 2023).

SB 9 (2021) — Duplexes and Lot Splits

Author: Sen. Toni Atkins. The lot-split bill. Cities must ministerially approve a duplex on a single-family parcel, and an urban lot split that divides one parcel into two — up to four homes where zoning once allowed one. It isn't an ADU statute, but it stacks with ADU law and changed what a single-family lot can hold.

SB 897 (2022) — Taller, Faster, Second Chances

Author: Sen. Bob Wieckowski. Guaranteed minimum heights (16 feet for most ADUs, more near transit), a hard 60-day approve-or-deny deadline with written corrections when an application falls short, and the first legalization framework for unpermitted ADUs — enforcement delay so owners can bring an existing unit up to code instead of tearing it out.

SB 477 (2024) — The Housekeeping Bill

Author: Senate Committee on Housing. No new rights — something just as useful. SB 477 reorganized and renumbered all of California's ADU and JADU statutes into one clean chapter of the Government Code (Sections 66310–66341), so the law homeowners and builders actually have to read finally lives in one place.

SB 1211 (2024) — Multifamily Expansion

Author: Sen. Nancy Skinner. Apartment properties joined the boom: a lot with an existing multifamily building can now add up to eight detached ADUs (no more than the number of existing homes on the lot), up from two — with relief from replacement-parking mandates when garages or carports make way.

SB 543 (2025) — The Clock Bill

Author: Sen. Jerry McNerney. Effective January 1, 2026: cities get 15 business days to tell you whether your ADU application is complete (no more silent resets of the 60-day clock), ADU size is measured by interior livable space, junior ADU law was aligned with ADU law, and applicants gained a formal appeal when a city denies a unit.

SB 543, in detail: the completeness notice is not a courtesy — it is a statutory deadline. Within 15 business days of receiving your application, the permitting agency must tell you in writing whether it is complete, and if it is not, list exactly what is missing and how to make it complete (Government Code Section 66317(a)(2)). If the agency calls your application incomplete or denies it, you now have a formal appeal, and the agency owes you a final written decision within 60 business days of your written appeal (Section 66317(d)(1)). SB 543 also tightened the money rules: a unit under 500 square feet of interior livable space does not increase assessable space, impact fees are barred on ADUs of 750 square feet or less and charged proportionally above that (Section 66311.5), and a city that fails to send HCD its adopted ADU ordinance — or ignores HCD’s findings — ends up with an ordinance that is null and void (Section 66326(d)). The sections below unpack each of these.

SB 1117 (2026) — The Fee-Cliff Fix

Author: Sen. Sabrina Cervantes. Signed September 29, 2026 and effective January 1, 2027. For your first two ADUs, local impact fees can only be charged on the living area above 750 square feet — a city can no longer bill you for the exempt first 750 the moment your unit comes in at 751 square feet. It also clarifies when ADUs are exempt from utility connection fees.

SB 1196 (2026) — No More Waiting on the Utility

Author: Sen. Jerry McNerney. Signed September 28, 2026 and effective January 1, 2027. Anyone who has finished an ADU and then waited months — sometimes up to a year — for the utility to hook it up knows the problem this bill targets. SB 1196 directs the California Public Utilities Commission to set clear timelines for processing utility service connections for ADUs and junior ADUs, and to establish penalties for utilities that fail to process those applications on time. You can also submit your hookup request at the same time as your building permit, and a utility cannot cancel your service connection application without your consent. The same timelines cover other small energization projects, like an EV charger or a home backup battery.

The Trend Line

Counting both houses, Sacramento amended ADU law 26 times between 2016 and 2024 — the Assembly bills (AB 68, AB 881, AB 2221, AB 1033, AB 2533 and others) sit alongside the Senate bills above, and the refinements keep coming. The direction has never reversed: every session makes ADUs easier to permit, cheaper to build, and harder for a city to block.

One related change from the other house: AB 956 — an Assembly bill, not a Senate bill — also takes effect January 1, 2027, and requires cities to approve up to two detached ADUs (up to 800 square feet each) on a lot with a single-family home.

The Statute in Plain English: Government Code Sections 66310–66342

Every bill on this page was ultimately written into one place: Chapter 13 of the Government Code, Sections 66310 through 66342 — the actual statute your city must follow. SB 477 (2024) gathered the scattered older sections (the old 65852.2 series some city handouts still cite) into this single chapter, and the 2025 bills renumbered a few pieces again. Here is the map, in the order a project meets it:

  • Sections 66310–66313 — the definitions. What counts as an ADU and a JADU, and the terms every other rule depends on: “interior livable space” (how size is now measured), “objective standards,” “permitting agency.”
  • Section 66314 — local ordinances. What a city may regulate by ordinance: objective development and design standards only, inside state-set floors and ceilings.
  • Section 66315 — owner occupancy. A city may not require owner occupancy for an ADU. (JADUs are the exception — see AB 1154 below.)
  • Section 66316 — the fallback. If a city has no ADU ordinance, or its ordinance falls out of compliance, the state standards in the statute apply directly to your permit.
  • Section 66317 — ministerial approval and the clocks. Completeness notice within 15 business days, approve-or-deny within 60 days of a complete application, deemed approved if the agency misses the deadline, written correction comments on a denial, and your right to appeal.
  • Sections 66321–66323 — size, height, setbacks, parking, and the guaranteed units. The dimensional floors a city cannot go below, plus the four categories of “66323 units” every city must approve ministerially: a conversion ADU (and a JADU) on a single-family lot, an 800-square-foot detached ADU, conversions inside multifamily buildings, and detached ADUs on multifamily lots.
  • Section 66311.5 — fees. No impact fees on ADUs of 750 square feet of interior livable space or less; proportional fees above that; utility connection charges proportionate to the unit’s actual burden.
  • Sections 66326 and 66333.5 — state review. Adopted ADU and JADU ordinances go to HCD for a compliance check (detailed below).
  • Sections 66333–66339 — the JADU article. The separate, tighter rulebook for junior ADUs: 500 square feet maximum, inside the walls of the house, deed restriction required.
  • Sections 66340–66342 — separate sale. Where a city opts in, an ADU can be sold separately from the main house as a condominium.

What to verify: which pathway your design uses — a Section 66323 category (state-guaranteed, almost no local standards allowed) or a Section 66314 ordinance unit (local objective standards may apply) — and whether your city’s ordinance is current. Ask the planning counter which one they are processing you under; the answer changes what they may lawfully demand.

Where projects get tripped up: old section numbers. City PDFs, HOA letters, and AI answers still cite Section 65852.2 — that is the pre-2025 numbering of the same law, and a counter argument built on it may be two renumberings out of date. The other classic trap: the statute sets your rights, but the building code (Title 24 and the California Residential Code) still governs how the unit is physically built. Winning the zoning argument does not waive a single structural, energy, or fire rule.

The HCD ADU Handbook: The State’s Own Instruction Manual

The California Department of Housing and Community Development (HCD) publishes the ADU Handbook — the state’s official, plain-language companion to the statute. The current edition is dated March 2026 and includes a December 2025 addendum covering the laws that took effect January 1, 2026. It is a free PDF (also published in Spanish, Vietnamese, and Chinese), written for homeowners, designers, builders, and city staff at the same time.

Why it matters to your project: planners, plan checkers, and HCD’s own reviewers all work from this document. It collects the statute summaries, the fee rules, the size and setback floors, and HCD’s answers to the questions cities actually ask — including the exact situations (shared bathrooms, coastal permits, unpermitted units) where projects stall. When a counter staffer states a rule that sounds wrong, the Handbook is the first document to open, and the one a city is most likely to accept as the tiebreaker.

What to verify: the edition date on the cover before you rely on any page of it — a downloaded copy from two years ago predates SB 543, AB 1154, and AB 462 entirely. The pitfall: the Handbook is HCD’s guidance, not the law itself. If the Handbook and the Government Code ever conflict, the statute controls — and the Handbook will not tell you your own city’s objective standards, local fees, or portal quirks, which is where most projects actually spend their time.

AB 1154 (2025) — The Junior ADU Owner-Occupancy Fix

Author: Assemblymember Juan Carrillo. Chapter 507, Statutes of 2025, effective January 1, 2026. Before AB 1154, every JADU carried a blanket owner-occupancy rule: the owner had to live in either the main house or the JADU, no exceptions. AB 1154 replaced that blanket rule with one keyed to the bathroom. Under Government Code Section 66333(b) as amended, a city may require owner occupancy only if the JADU shares sanitation facilities with the existing house. Give the JADU its own separate bathroom and no owner-occupancy may be required at all — and owner occupancy is never required when the owner is a government agency, land trust, or housing organization. The same bill confirmed in Section 66333(g) that a JADU rental must be for a term longer than 30 days: no short-term rentals.

What to verify: whether your JADU design has a fully separate bathroom — that single design decision now determines whether you can rent out both the house and the JADU while living elsewhere. The owner-occupancy that still applies to shared-bathroom JADUs lets the owner live in either portion of the house.

Where projects get tripped up: the deed restriction did not go away — a JADU still requires a recorded deed restriction (no separate sale, size and attribute limits) that runs with the land and binds future buyers. And expect some cities to keep quoting the old blanket rule from their pre-2026 JADU ordinances: the statute controls, and Section 66333(b) is the text to point to — politely, in writing.

AB 462 (2025) — Disaster Recovery: Move Into the ADU First

Authors: Assemblymembers Josh Lowenthal and Robert Rivas. Chapter 491, Statutes of 2025 — an urgency measure, in effect since October 10, 2025. AB 462 was written for the Los Angeles fire recovery, and it changes two rules that were slowing rebuilding. First, Government Code Section 66328: normally a city cannot issue a certificate of occupancy for an ADU before the main house gets its own. In a county under a Governor’s state-of-emergency proclamation issued on or after February 1, 2025, that order flips — if the primary dwelling was substantially damaged or destroyed by the emergency event, the city must issue the ADU’s certificate of occupancy once the ADU is permitted and has passed all required inspections, even while the main house is still being rebuilt. A family can live in the new ADU on its own lot during the reconstruction. Second, Section 66329 puts coastal ADUs on a clock: a coastal development permit application for an ADU must be approved or denied within 60 days of a complete application, reviewed concurrently with the building permit — and a locally issued coastal permit for an ADU can no longer be appealed up to the Coastal Commission. If the Coastal Commission itself holds the application and misses the 60 days, the application is deemed approved.

What to verify: that your county is actually under a qualifying proclamation (the February 1, 2025 cutoff matters) and that the damage to the primary dwelling is documented as caused by the emergency event — that causal link is the trigger for the early occupancy right.

Where projects get tripped up: two limits surprise people. The early-occupancy rule does not apply to an ADU attached to the destroyed primary dwelling (Section 66328(c)) — the ADU has to stand on its own. And the headline version of this bill — a blanket exemption from coastal permits — was amended out before passage: coastal ADUs still need the coastal permit, just on a 60-day clock instead of an open-ended one. The ADU’s certificate of occupancy also does not permit, excuse, or accelerate the main-house rebuild itself, which still goes through its own process.

Objective Standards: The Only Kind of Local Rule a City Can Add

State law lets cities write their own ADU ordinances — but only with objective standards. The definition is in Section 66313(i): a standard that involves no personal or subjective judgment by a public official, and that can be verified uniformly against an external benchmark that both the applicant and the official can know before the application goes in. Height limits, setbacks, lot coverage, landscaping, maximum size — numbers and checklists. Under Section 66314(b)(1), a local ordinance may impose objective development and design standards of that kind. For the state-guaranteed Section 66323 units, the city may not layer on standards beyond what Section 66323 itself allows at all.

What to verify: before you design, get the city’s published objective standards — ideally its ADU checklist — in writing. Every condition the city applies to a ministerial ADU should trace to a published, measurable standard. If a requirement cannot be measured, it is probably not objective.

Where projects get tripped up: subjective conditions dressed as standards — “compatible with neighborhood character,” “harmonious design,” a design-review board’s discretionary approval, or a neighbor-consent condition. Those convert a ministerial approval into a discretionary one, which is exactly what state law forbids for ADUs, and they are among the most common findings in HCD’s ordinance reviews. Undocumented counter requirements that appear in no ordinance and no checklist are the everyday version of the same problem: ask for the citation, in writing.

How Your City’s ADU Ordinance Gets Reviewed by the State

Local ADU ordinances do not grade themselves. Under Government Code Section 66326 (and Section 66333.5 for JADU ordinances), a city that adopts an ADU ordinance must send a copy to HCD within 60 days of adoption. HCD reviews it against state law and may send written findings. The city then has 30 days to respond — either amend the ordinance to match HCD’s findings, or re-adopt it with a resolution explaining why it believes the ordinance complies anyway. If the city misses the submission deadline or ignores the findings, the consequence is severe: the ordinance is null and void, and the city must permit ADUs under state law alone. HCD can also notify the city — and the Attorney General — that it is in violation. A city may also choose to adopt no ordinance at all; in that case the statute is the entire rulebook, which is often the better deal for the homeowner.

What to verify: if your city is enforcing a local rule that seems stricter than the state floors on this page — a bigger setback, a smaller size cap, an extra hearing — ask two questions: has this ordinance been submitted to HCD, and what did HCD’s findings say? Both are public, and the answers explain a surprising share of counter-level confusion.

Where projects get tripped up: timing. Ordinances adopted before the 2025 and 2026 laws took effect may still be quoted at the counter months after Sacramento overrode them, and a null-and-void ordinance can keep being applied until someone raises it. The raise works best as a written question citing the section — which is exactly what the next two sections are for.

If a City Won’t Follow State Law: HCD Enforcement

HCD is not just a publisher. It has reviewed local ADU ordinances since 2016, and since January 1, 2024 it has had authority to enforce state ADU law generally — working through its Housing Accountability Unit (HAU), the enforcement team HCD built with 2021–22 budget funding to hold jurisdictions to state housing law. The enforcement ladder starts soft — education and technical assistance to the city — and escalates through written findings letters on non-compliant ordinances. If a city will not fix a violating ordinance, HCD shall notify the city and may notify the Attorney General that the city is in violation of state ADU law (Section 66326(c)(1)), and housing-law violations can carry consequences up to revocation of the city’s housing element certification. While an ordinance is out of compliance, the city is supposed to apply the state standards directly (Section 66316).

What to verify: that you are dealing with a legal violation and not a lawful local standard — HCD enforces the statute, not preferences. The Handbook’s ordinance-review findings and the sections above are the test. The pitfall: enforcement runs against the jurisdiction, on the state’s timetable. It fixes the rule for everyone; it does not re-decide your individual permit, which is why the appeal and complaint routes below exist in parallel.

Filing a Complaint With the Housing Accountability Unit

When a city denies an ADU in a way that conflicts with state law, refuses the 60-day clock, or applies a standard that appears nowhere in its ordinance, a homeowner can put the facts in front of HCD. The working route, per HCD’s own Handbook:

  1. Get it in writing locally first. A denial or incompleteness determination must come with written comments listing what is defective and how to fix it. Paper is what reviewers act on.
  2. Use the local appeal SB 543 guarantees (Section 66317(d)): appeal the denial or incompleteness call in writing; the agency owes a final written determination within 60 business days. Run this clock — do not let a complaint elsewhere substitute for it.
  3. Send the facts to HCD through its online ADU portal, linked from HCD’s ADU program page. HCD asks for as much detail as possible and may request the denial and your communications with the local agency — attach them from the start.
  4. HCD and the HAU review. Education and technical assistance to the city come first; documented, repeated violations are what escalate toward findings letters and Attorney General referral.

Where complaints get tripped up: expectations. The HAU does not reverse your permit, order the city to pay you, or act as your lawyer — it enforces state law against jurisdictions. Timelines are measured in months, not days, so keep your local appeal and your project schedule moving in parallel, and keep every letter, email, and portal notice from the city in one file. For a high-value project stuck on a legal question, that file is also what a land-use attorney will ask to see first.

School District Fees on an ADU: The 500-Square-Foot Line

School fees are their own category — charged not by your city but by your local school district, under Education Code Section 17620 and the Mitigation Fee Act. The ADU-specific rule turns on one number: 500 square feet of interior livable space. An ADU or JADU under that line does not increase “assessable space,” so no school impact fee may be charged on it — a point SB 543 wrote explicitly into Section 66311.5 in 2026 to end district-by-district disagreement. Above 500 square feet, a school district may levy its developer fee on the unit (it is authorized to, not required to), calculated on the unit’s square footage like other residential construction.

What to verify: your district’s current fee schedule and whether it has adopted fees reaching ADUs — and get its clearance paperwork handled before final inspection, since districts typically collect at permit issuance and the certificate is part of the file the building department expects.

Where projects get tripped up: confusing the two fee systems. The city’s impact-fee exemption (nothing owed on an ADU of 750 square feet or less, Section 66311.5) does not exempt a 600-square-foot ADU from the school district’s fee — different government, different statute, different threshold. Budget the school fee into any design between 501 and 750 square feet, and if a district bills a unit that is under 500 square feet of interior livable space, ask it to reconcile the bill with Section 66311.5 and Education Code Section 17620 before you pay.

This Page Is a Living Law Hub — Sources and Updates

ADU law in California changes almost every legislative session, and this page is maintained as ADU Cities’ law hub: it is updated as new bills are chaptered and as HCD revises its guidance, most recently against HCD’s March 2026 Handbook edition. The bills above that are signed but not yet in force — SB 1117 and SB 1196, both effective January 1, 2027 — are flagged where they appear, and the same will happen to the next session’s bills. Primary sources used on this page:

The pitfall this guards against: stale law. A printout, a saved PDF, or a blog post from even one session ago can state rules Sacramento has already replaced — owner occupancy, fee thresholds, and timelines have all changed within the last two years. Check the effective date on anything you rely on, verify parcel-specific requirements with your city or county before you submit, and treat this page as general information, not legal advice.

What This Means for Your Lot

These laws are why a project a city would have rejected in 2015 is approved by right today. If you want to know what your parcel can carry under current law, call or text 562-810-1965 for a free consultation. ADU Cities is built by Mars Construction Industries Corp — CSLB #1138550 (A General Engineering, B General Building, C-36 Plumbing, C-20 HVAC).

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