AB 1055 amends Government Code Section 66315 to give counties and cities the explicit authority to require proof of residential occupancy when they apply streamlined rules to accessory dwelling units (ADUs) and junior ADUs. The bill requires the property owner to certify that the ADU will be occupied as a residence for at least six months in each calendar year, allows annual self-recertification for the first 10 years, and constrains enforcement—mandating at least two notices, banning demolition as a penalty, and limiting fines to a “reasonable” amount defined by reference to existing statute.
This change grafts a compliance layer onto California’s ADU streamlining regime. For local planners and compliance officers it creates a formal path to police conversion of ADUs into short-term rentals; for homeowners and developers it creates recurring paperwork and modest enforcement risk that could affect the economics of building and operating ADUs.
At a Glance
What It Does
The bill authorizes local agencies to require proof of residential occupancy for any streamlined ADU or junior ADU approval, obliges owners to certify six months of residential use per calendar year, and permits annual self-recertification for the first 10 years. It also prescribes minimum notice steps for enforcement and bars demolition as a sanction while capping fines to a statutory “reasonable” amount.
Who It Affects
Directly affects homeowners who add or operate ADUs, local planning and code-enforcement departments that process ADU permits, short-term rental hosts and property managers, and ADU builders and investors who rely on rental income projections.
Why It Matters
AB 1055 inserts a compliance mechanism into a statute designed to limit local additional standards for ADUs, potentially reducing the conversion of ADUs into short-term rentals but also adding administrative work and compliance risk that could dampen ADU production or change how owners rent them.
More articles like this one.
A weekly email with all the latest developments on this topic.
What This Bill Actually Does
California law generally restricts local governments from imposing additional standards on ADU approvals beyond state-mandated limits; those limits are meant to speed up approvals and lower barriers. AB 1055 adjusts that balance by allowing a local agency, when it applies streamlined approval procedures, to demand evidence that the unit is used as a residence.
The authorization covers accessory dwelling units and junior ADUs and applies to any processes that qualify as “streamlining” under current law.
Under the bill an owner must certify that the ADU will be occupied as a residential dwelling for at least six months of each calendar year. The statute expressly says that certification is not made under penalty of perjury, which keeps the statement administrative rather than criminal.
To sustain oversight without indefinite paperwork, the bill limits the agency’s annual recertification authority to the first 10 years after the unit is built or permitted, and it contemplates the recertification can be done by the owner as a self-certification.If a local agency enforces the recertification obligation it must provide at least two notices to the owner before taking further action. The bill also limits punitive responses: agencies cannot require demolition of an ADU solely for failing the six-month rule, and fines for noncompliance are capped at a “reasonable” level (the text points back to an existing statutory definition).
What the bill does not do is prescribe the form of “proof” (utility bills, leases, affidavits, etc.), nor does it set out audit procedures or penalties for false self-certification, leaving those implementation details to local ordinance or practice.The practical effects are mixed. Cities and counties get a legal tool to discourage use of ADUs as predominantly short-term rentals, which can protect local housing stock and neighborhood character.
But owners face recurring compliance steps across up to a decade, and local governments must create notice-and-tracking systems, decide acceptable evidence, and choose whether to audit self-certifications—actions that consume staff time and create legal risk if applied unevenly.
The Five Things You Need to Know
The bill authorizes local agencies to require proof of residential occupancy as a condition of any ADU or junior ADU streamlining.
Owners must certify the ADU will be occupied at least six months during each calendar year; that certification is explicitly not under penalty of perjury.
A local agency may require annual recertification by owner self-certification for the first 10 years after approval.
Enforcement must include at least two notices to the owner, and local agencies may not order demolition for non-use; fines are limited to a “reasonable” amount identified by reference to Section 25132(c).
AB 1055 adds this compliance pathway while operating inside the preemption framework of Section 66314, which otherwise prevents local owner-occupancy and additional standards except where state law permits.
Section-by-Section Breakdown
Every bill we cover gets an analysis of its key sections.
Existing exception for 30-day rental minimum
This subsection preserves the existing allowance that a local agency may require the property be used for rentals of 30 days or longer. Practically, it reiterates that short-term rental restrictions are already a permitted local carve‑out and remains separate from the new proof-of-occupancy provisions; local ordinances that already enforce minimum rental terms can continue to do so alongside any certification regime the agency adopts.
Authorization to require proof of residential occupancy
The bill inserts a clear authorization for local agencies to demand proof when they apply streamlined ADU rules. That means cities and counties can condition streamlined approvals on evidence the unit will be used residentially, but the bill leaves the type and stringency of acceptable evidence unspecified—delegating those choices to local implementation and creating potential variation across jurisdictions.
Owner certification: six-month occupancy rule
This clause obliges the property owner to certify that the ADU will be occupied as a residential dwelling for at least six months each calendar year and states the certification is not under penalty of perjury. Making the certification non-criminal simplifies administration but reduces leverage for criminal penalties in cases of false statements; enforcement therefore depends on administrative follow-up or civil fines rather than perjury prosecution.
Annual self-recertification for 10 years
The statute permits annual recertification by owner self-certification for the first 10 years after the ADU is permitted. Limiting the recertification window to a decade restricts local oversight to the early life of the unit—when jurisdictions may be most concerned about conversions to short-term rentals—but also creates a sunset point after which the owner generally faces no further state-authorized reporting under this provision.
Enforcement steps, limits, and fines
Before taking enforcement action under the recertification rules, a local agency must provide at least two notices to the owner. The bill bars demolition of an ADU as a remedy for failing the six-month occupancy rule and limits fines to a “reasonable” amount by referencing Section 25132(c). Those limits narrow the spectrum of sanctions available to local governments, steering enforcement toward notice and modest financial penalties rather than more disruptive remedies.
This bill is one of many.
Codify tracks hundreds of bills on Housing across all five countries.
Explore Housing in Codify Search →Who Benefits and Who Bears the Cost
Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- Neighborhood residents concerned about short-term rentals — the certification and recertification tool gives local governments a statutory basis to discourage conversions of ADUs into predominantly short-term units, supporting more stable occupancy.
- Local planning and code-enforcement departments — the bill provides a clear legal mechanism to track ADU occupancy and to justify administrative follow-up when units appear to function as short-term rentals.
- Long-term renters seeking housing stock — by reducing the attractiveness of running an ADU solely as a short-term rental, the measure may increase the supply of units available for longer-term leases in some markets.
- Municipalities aiming to preserve local services and parking balance — predictable residential occupancy makes it easier for cities to plan for infrastructure and neighborhood impacts tied to permanent residents.
Who Bears the Cost
- Homeowners who create ADUs — they must complete initial certification and up to 10 annual self‑recertifications, adding administrative burden and potential exposure to fines for noncompliance.
- Local governments — planning and code departments must design notice and tracking systems, decide acceptable forms of proof, and allocate staff time to process recertifications and enforce compliance.
- ADU builders and investors — added compliance and potential limits on short-term rental income could lower expected returns and discourage some projects, particularly in high STR-demand areas.
- Short-term rental hosts and property managers who rely on ADU income — the statute creates a legal foundation for restricting STR use of ADUs, reducing revenue opportunities for operators who manage short-term stays.
Key Issues
The Core Tension
The central tension is between preserving the state’s streamlining of ADU approvals (to increase housing supply) and giving local governments tools to ensure ADUs function as long-term housing rather than short-term rentals; strengthening enforcement tools reintroduces friction that streamlining aimed to eliminate, forcing a choice between administrative simplicity and local control over residential character.
AB 1055 builds enforcement authority into a statute whose primary purpose is to remove local barriers to ADU construction. That combination produces several implementation risks.
First, the bill leaves the operative meaning of “proof” undefined; local agencies must decide whether to accept leases, utility bills, occupancy declarations, or other records, and those choices will drive both compliance costs and litigation risk. Second, the certification is explicitly not under penalty of perjury and the recertification is a self-declaration for up to 10 years, which limits the state’s ability to pursue false statements criminally and shifts the burden to administrative checks or audits that many local agencies are not resourced to perform.
Third, enforcement constraints—requiring two notices, barring demolition, and capping fines—protect owners from draconian penalties but may blunt deterrence. The bill references a “reasonable” fine under Section 25132(c), yet that cross-reference may not deliver predictable sanction levels across jurisdictions.
Finally, there is a behavioral trade-off: stricter certification regimes discourage ADUs from being used as STRs but may also chill ADU production by increasing ongoing compliance costs and uncertainty for owners and investors.
Try it yourself.
Ask a question in plain English, or pick a topic below. Results in seconds.