What Are Your ADU Rights Under California Civil Code?

Your Legal Rights to Build an ADU in California

California has established itself as the national leader in Accessory Dwelling Unit (ADU) legislation, with a comprehensive framework of laws that protect homeowners' rights to build, occupy, and rent ADUs on their property. These protections are codified in the California Civil Code, the Government Code, and various pieces of legislation passed over the past decade.

Understanding your rights under California law is critical whether you are planning to build an ADU, facing opposition from your city or HOA, or simply want to understand what the law allows. This guide provides a thorough overview of every key right and protection available to California ADU homeowners.

Your Right to Build an ADU

California Government Code Sections 65852.2 and 65852.22 establish the fundamental right of California homeowners to build ADUs and Junior ADUs (JADUs) on properties zoned for residential use. This right has been progressively strengthened through a series of legislative actions.

Key Construction Rights

Under current California law, you have the right to build at least one ADU on any residentially zoned lot that already has an existing or proposed single-family or multifamily dwelling. Additionally, you have the right to build one JADU (Junior ADU) in addition to a standard ADU on single-family lots. Your local jurisdiction cannot impose minimum lot size requirements that would effectively prevent ADU construction on your property. Cities must approve ADUs that meet state standards within 60 days of receiving a complete application.

Size Protections

California law sets minimum size protections to ensure that local jurisdictions cannot make ADUs impractically small. Your jurisdiction must allow ADUs of at least 800 square feet, with a minimum height of 16 feet, regardless of local zoning restrictions that might otherwise apply. For JADUs, the maximum size is 500 square feet, and they must be created within the existing or proposed single-family residence.

Setback and Parking Protections

California law places strict limits on the setback and parking requirements that local jurisdictions can impose on ADU projects.

Setback Protections

For new construction ADUs, the maximum rear and side setback that a local jurisdiction can require is four feet. This is a significant protection because many cities previously required setbacks of 10, 15, or even 20 feet, which effectively prevented ADU construction on smaller lots.

For garage conversions and ADUs built within existing structures, no additional setbacks are required. If the existing structure already encroaches into the setback area, the ADU can maintain that same footprint.

Parking Protections

One of the most impactful ADU protections in California law is the elimination of parking requirements in many situations. Your jurisdiction cannot require additional parking for your ADU if the property is located within half a mile of a public transit stop, within an architecturally and historically significant historic district, on a street where a car-share vehicle is available within one block, or when the ADU is part of an existing primary residence or accessory structure (such as a garage conversion).

Even when parking can be required, the maximum is one space per ADU, and the parking can be provided as tandem parking on an existing driveway. These protections have been transformative for ADU development in Los Angeles and other urban areas where parking is scarce.

Fee and Impact Fee Protections

California law protects homeowners from excessive fees that could make ADU construction financially impractical.

Impact Fee Exemptions

ADUs under 750 square feet are completely exempt from all impact fees, including school fees, park fees, and utility connection fees. For ADUs 750 square feet and larger, impact fees must be charged proportionally based on the size of the ADU relative to the primary dwelling. This means the fees for a 900-square-foot ADU should be significantly less than those charged for a new single-family home.

Utility Connection Fee Protections

Local agencies, including water and sewer districts, cannot require a new or separate utility connection for ADUs built within existing structures. For new construction ADUs, connection fees must be proportional to the ADU's burden on the system, not the standard fees charged for new single-family homes.

HOA and CC&R Protections

California Civil Code Section 4751 provides critical protections for homeowners in HOA-governed communities. Any provision in HOA governing documents (CC&Rs, bylaws, rules, or regulations) that effectively prohibits or unreasonably restricts ADU construction or use is void and unenforceable.

For a detailed analysis of your rights when dealing with HOA resistance, see our comprehensive guide on whether your HOA can block your ADU project.

What HOAs Can and Cannot Do

HOAs can impose reasonable design and architectural standards that do not significantly increase the cost of the ADU or unreasonably delay the project. They can require the ADU to be architecturally compatible with the existing community, require submission of plans for architectural review, and set reasonable construction guidelines.

HOAs cannot outright prohibit ADU construction, prohibit long-term rental of ADUs, impose size restrictions below state minimums, charge excessive fees for ADU review, or use delay tactics to effectively prevent construction.

Your Right to Rent Your ADU

California law protects your right to rent your ADU, with some important nuances.

Long-Term Rental

You have the right to rent your ADU for long-term tenancies (30 days or more). No local jurisdiction or HOA can prohibit this. Your ADU tenants have the same rights as any other California tenant under state landlord-tenant law.

Short-Term Rental Limitations

Local jurisdictions can impose short-term rental restrictions on ADUs. Many cities, including Los Angeles, require that ADU rentals be for terms of 30 days or more. This means platforms like Airbnb or VRBO may be restricted depending on your local ordinance.

Owner-Occupancy Requirements

Under current law, there is no statewide owner-occupancy requirement for ADUs built after January 1, 2020. This means you can rent both your main home and your ADU without living on the property. Some cities may have attempted to impose local owner-occupancy requirements, but these have been largely preempted by state law for ADUs permitted after 2020.

Permit Processing Rights

California law ensures that local jurisdictions process ADU permit applications in a timely manner.

60-Day Processing Requirement

Once you submit a complete ADU permit application, your local jurisdiction must act on it within 60 days. If the jurisdiction fails to act within 60 days, the application is deemed approved. This provision prevents cities from using indefinite delays to discourage ADU construction.

What Constitutes a "Complete" Application

A complete application includes all required forms, plans, and fees. If your application is incomplete, the jurisdiction must notify you within a reasonable timeframe and identify the specific items needed. The 60-day clock starts when all deficiencies are corrected and the application is deemed complete.

Pre-Approved Plans

Many California jurisdictions now offer pre-approved ADU plans that can further streamline the permitting process. Using a pre-approved plan can reduce the review time and ensure compliance with local codes. Check with your city to see if pre-approved plans are available. Understanding the full ADU permit process in Los Angeles helps you navigate this efficiently.

Recent Legislative Changes Expanding ADU Rights

California continues to expand ADU rights through new legislation. Here are the most significant recent changes that affect your rights as an ADU homeowner.

SB 9 (California Housing Opportunity and More Efficiency Act)

While not specifically an ADU law, SB 9 allows lot splits and duplexes on single-family zoned lots, which can be combined with ADU provisions to significantly increase housing density on a single property.

AB 2221 (2022)

This bill clarified several ADU provisions, including confirming that front setback requirements cannot be imposed on ADUs that do not exceed the existing setback of the primary structure, and that jurisdictions must allow ADUs on lots with existing multifamily dwellings.

SB 897 (2022)

SB 897 increased the minimum height that jurisdictions must allow for detached ADUs to 16 feet, and to 18 feet in some circumstances. It also clarified that ADUs should be allowed on properties with existing nonconforming uses.

AB 1033 (2023)

This groundbreaking legislation allows ADUs to be sold separately from the primary dwelling through a condominium-like arrangement. While implementation details vary by jurisdiction, this law opens up new possibilities for ADU ownership and financing.

Enforcing Your ADU Rights

If your rights are being violated by your local jurisdiction, HOA, or other entity, there are several enforcement mechanisms available to you.

Filing a Complaint with HCD

The California Department of Housing and Community Development (HCD) oversees compliance with ADU laws. You can file a complaint with HCD if your local jurisdiction is imposing requirements that violate state ADU law. HCD has the authority to investigate complaints and require jurisdictions to comply with the law. The complaint process is straightforward: you submit a written description of the violation, including the specific ADU law being violated and the name of the jurisdiction. HCD will investigate and work with the jurisdiction to resolve the issue, often within 30 to 90 days.

Legal Action

In some cases, you may need to pursue legal action to enforce your rights. California courts have been receptive to ADU-related claims, and several precedent-setting decisions have reinforced homeowners' rights. An attorney experienced in land use and ADU law can advise you on the best course of action. Common legal claims include mandamus actions (asking the court to order the city to issue a permit), declaratory relief (asking the court to declare that a specific restriction violates state law), and damages claims for economic losses caused by illegal permit denials or delays.

Attorney General Enforcement

The California Attorney General has the authority to take action against jurisdictions that violate ADU laws. In several instances, the AG's office has sent letters to non-compliant cities, resulting in policy changes without the need for litigation. The AG has specifically targeted cities that impose illegal parking requirements, excessive impact fees, and owner-occupancy restrictions on ADUs permitted after 2020.

Design and Construction Rights

Your rights under California law extend to specific aspects of ADU design and construction that many homeowners may not be aware of.

Right to Choose Your Design

While local jurisdictions can enforce objective design standards (such as setbacks, height limits, and lot coverage), they cannot require discretionary design review for ADU projects that meet these standards. This means a planning commission or design review board cannot reject your ADU based on subjective opinions about aesthetics. If your ADU meets all objective development standards, it must be approved.

Right to Garage Conversion

California law specifically protects your right to convert an existing garage, carport, or covered parking structure into an ADU. When you convert a garage, the city cannot require you to replace the lost parking spaces. This is one of the most cost-effective ways to create an ADU, as the existing structure provides a foundation, walls, and roof that can be adapted for residential use. See our guide on garage conversion costs and process.

Right to Build on Multifamily Properties

If you own a property with an existing multifamily dwelling (such as a duplex, triplex, or apartment building), you have the right to add ADUs. For multifamily properties, you can convert existing non-habitable space (such as storage rooms, laundry rooms, or basements) into ADUs, and you can add detached ADUs up to the number allowed by your jurisdiction's ordinance. This provision has opened up significant opportunities for property owners looking to maximize the housing potential of their multifamily lots.

Right to Sell Your ADU Separately (AB 1033)

One of the most significant recent developments in California ADU law is AB 1033, which allows ADUs to be sold separately from the primary dwelling through a condominium-like arrangement. While not all jurisdictions have opted into this program, it represents a groundbreaking shift in how ADUs are treated in the California housing market. If your jurisdiction participates, you could potentially sell your ADU as an independent unit, opening up new investment and ownership possibilities.

ADU Tenant Rights and Landlord Obligations

When you rent your ADU, both you and your tenants have specific rights and obligations under California law.

Tenant Protections

ADU tenants in California are protected by the same landlord-tenant laws that apply to all rental housing in the state. This includes the California Tenant Protection Act (AB 1482), which limits annual rent increases to 5% plus the local rate of inflation (or 10%, whichever is lower) for properties that are more than 15 years old, and provides just-cause eviction protections. However, single-family homes where the owner occupies the primary residence may be exempt from some of these provisions. Consult with a landlord-tenant attorney to understand which protections apply to your specific situation.

Habitability Standards

As a landlord, you are required to maintain your ADU in a habitable condition. This includes providing adequate weatherproofing, plumbing, heating, electrical systems, sanitation, and structural integrity. All building code requirements must be met and maintained throughout the tenancy. If your ADU was properly permitted and passed all inspections, you should already meet these standards, but ongoing maintenance is your responsibility.

Security Deposits

California law limits security deposits for ADU rentals to the same amounts as other residential rentals: one month's rent for unfurnished units and two months' rent for furnished units. You must return the deposit within 21 days of the tenant's departure, minus any legitimate deductions for cleaning and damage beyond normal wear and tear.

Frequently Asked Questions About ADU Rights in California

Can my city deny my ADU permit if I meet all state requirements?

If your ADU project complies with all applicable state standards, your city should not deny the permit. However, if your project requires discretionary approval (which is rare for ADUs that meet objective standards), there may be additional review. If you believe your permit was wrongly denied, you can appeal to HCD or pursue legal remedies.

Do I have the right to build an ADU on a multifamily property?

Yes. California law allows ADUs on lots with existing multifamily dwellings. The specific rules vary depending on the number of existing units and the type of ADU proposed, but the right to build is established in Government Code Section 65852.2.

Can my city require me to live on the property if I build an ADU?

For ADUs permitted after January 1, 2020, there is no statewide owner-occupancy requirement. Your city should not be imposing this requirement for ADUs permitted after this date. JADUs, however, do require owner-occupancy of either the JADU or the primary dwelling.

What if my city charges impact fees that seem too high?

If your ADU is under 750 square feet, you should not be charged any impact fees. For larger ADUs, fees must be proportional. If the fees seem excessive, request an itemized breakdown and compare them to what would be charged for a comparable addition to an existing home. You can challenge excessive fees through the permit appeal process or by filing a complaint with HCD.

Can I build an ADU if my existing home does not conform to current zoning?

Yes. California law clarifies that ADUs should be allowed on properties with existing nonconforming structures, provided the ADU itself meets the applicable development standards. Your existing home's nonconforming status should not prevent you from building an ADU.

Are there any restrictions on who can live in my ADU?

No. California law does not restrict who can occupy an ADU. You can use it for family members, long-term tenants, or even as your own primary residence. Fair housing laws apply to ADU tenancies just as they do to any other rental property in California.

What is the difference between a JADU and an ADU under California law?

A Junior ADU (JADU) is a smaller unit of up to 500 square feet that is created within the existing walls of the primary residence. JADUs have different requirements than standard ADUs, including mandatory owner-occupancy of either the JADU or the primary dwelling, simplified building code requirements, and no requirement for a separate utility connection. A property can have both an ADU and a JADU, effectively allowing up to three units on a single-family lot.

Can my city require me to add a parking space for my ADU?

California law prohibits cities from requiring additional parking for ADUs in several situations: if the ADU is within half a mile of public transit, if the ADU is within a historic district, if the ADU is part of an existing or proposed primary residence, if on-street parking permits are available in the area, and if the ADU is a garage conversion. When parking is required, it can be provided as tandem parking or in setback areas, and no more than one space per ADU can be required.