Can an HOA Prevent an ADU in California?

TL;DR: Can an HOA Prevent an ADU?

• In California, an HOA cannot legally prohibit an ADU that complies with state law.
• HOAs may impose reasonable restrictions on exterior design, height, and setbacks, but those rules cannot effectively block construction.
• State ADU laws override any HOA rules or CC&Rs that attempt to ban or unreasonably restrict ADUs.
• Homeowners should review HOA governing documents and align plans with both state requirements and community design standards.
• Disputes may arise during design review, but homeowners have legal protections against burdensome restrictions.
• This article explains what HOAs can regulate, what they cannot, and how to navigate approval.

What Power Does an HOA Have in California?

HOAs have tremendous power over the neighborhoods that they govern. They can mandate and enforce certain aesthetic requirements and “community standards.”

These “community standards” typically have to do with how property owners use, maintain, or alter the appearance of their primary residence. There also may be rules that pertain to community living. For example, an HOA may have rules when it comes to street parking, noise levels, and pets. By living within an HOA, you agree to abide by these rules. Failure to do so can result in a fine.

The state of California mostly allows HOAs to set and enforce their own rules without interference. ADUs, however, are an exception. The state of California is invested in the building of ADUs as a way to create more affordable housing units and help alleviate the state’s housing crisis. Because of this, they’ve passed laws that prevent HOAs from banning most ADUs outright. They do allow HOAs to set what is called “reasonable restrictions,” though, when it comes to ADU size and appearance.

HOAs can enforce community standards but cannot impose restrictions that contradict state ADU laws.

California ADU Laws That Impact HOAs

If you’re a homeowner who is part of an HOA and looking to add a granny flat or casita to your single-family residence, there are 2 laws you should familiarize yourself with: AB 670 and Civil Code Section 4751. These laws prevent HOAs from banning ADUs outright and also stop them from placing burdensome restrictions that might ultimately prevent an ADU build.

AB 670 – Restrictions on Homeowners Associations Regarding ADUs

AB 670 was passed in 2019 to ensure association members maintained certain rights when it came to ADUs. It states that HOAs can’t ban the construction of accessory dwelling units or junior accessory dwelling units (JADUs) outright, though it does allow HOAs to require that homeowners follow certain design standards and height limits when building an ADU on their property. These usually mirror the design standards for the owner’s primary home and the neighboring houses.

Key Provisions

While AB 670 prevents HOAs from banning secondary housing units outright, giving some power back to individual homeowners, HOAs still have the power to place certain restrictions on the building of ADUs.

These include:

• Design standards. HOAs can mandate that any ADUs or in-law units built on a single-family residence follow certain design standards when it comes to style, paint color, etc.
• Setback requirements. An HOA can require that ADUs follow certain setback requirements. These association setback requirements can’t be greater than 4 feet from the rear or side property lines.
• Height & size limits. An HOA can impose certain height or size limits that can differ from those of the city’s building department. For example, while the city of San Diego allows for ADUs to be as large as 1200 square feet, an HOA in San Diego can have a different maximum size.

While AB 670 does allow HOA boards to set certain regulations, these can’t be overly burdensome – Meaning, they can’t be so restrictive that they prevent the homeowner from ever getting past the approval process. These rules are also restricted to the ADU’s exterior. Homeowners maintain the right to choose whatever interior design and floor plan they wish. ADU applications in California are reviewed ministerially, meaning local agencies must approve compliant projects within state-defined timelines, regardless of HOA preferences.

Civil Code Section 4751 – Enforcement Against Unreasonable Restrictions on ADUs

Civil Code Section 4751 is part of California’s AB 318, and it provides specific guidelines about what a burdensome or unreasonable restriction might be when it comes to ADUs. For example, if building a guest house would result in huge fees or HOA fee increases, this would be viewed as unreasonable.

Civil Code Section 4751 also allows homeowners to use their ADU as a rental unit without HOA interference. This supports the state’s belief that ADUs are important to help with the state’s housing shortage.

California ADU laws limit HOA restrictions, ensuring homeowners have the right to build with reasonable design standards.

Key Provisions

Civil Code Section 4751 prevents HOAs from placing unreasonable restrictions when it comes to additional costs, design guidelines, or permitting processes that would effectively prohibit the construction of an ADU that otherwise complies with state law. If a homeowner does feel like their HOA restrictions are unreasonable, Civil Code Section 4751 also gives them the right to seek legal advice and even take legal action against the board of directors to get the HOA to change their guidelines.

This provision also prevents HOAs from interfering with a property owner’s right to use their ADU as a rental unit and earn extra income, though it does allow for HOAs to ban short-term rentals under 30 days.

Can an HOA Restrict ADU Rentals?

California law allows homeowners to rent their ADU, and HOAs cannot prohibit long-term rentals that comply with state law. However, HOAs may restrict short-term rentals under 30 days.

What HOAs May Regulate

• Minimum rental terms (e.g., 30-day minimum)
• Community-wide short-term rental bans
• Noise and occupancy standards

What HOAs Cannot Do

• Ban long-term ADU rentals
• Require owner occupancy for most ADUs
• Increase dues solely because you built an ADU

Quick Answers

• Can I use my ADU for Airbnb? Possibly not. Many HOAs restrict short-term rentals.
• Can my HOA require me to live in the main home? Generally no, unless limited JADU rules apply.
• Can the HOA increase my monthly dues for renting my ADU? No, unless applied uniformly and not targeted at ADUs.

Owner-Occupancy Rules for ADUs and JADUs

California no longer requires owner occupancy for most ADUs. However, JADUs may still have limited owner-occupancy rules depending on configuration. This means you can typically rent out both your primary home and ADU without living on the property. Recent updates to California ADU law clarify that owner-occupancy requirements generally do not apply to ADUs, and HOAs cannot impose stricter occupancy rules that conflict with state law.

Key Differences

• ADU: No owner-occupancy requirement
• JADU: May require owner occupancy if sharing sanitation facilities

Quick Answers

• Do I have to live on the property if I build an ADU? No, in most cases.
• Can an HOA require owner occupancy? No, if state law prohibits it.
• Does this apply in condos? Condo developments may have additional complexity depending on shared systems.

Do HOA Rules Override California ADU Law?

No. California state ADU law supersedes any HOA rule or CC&R provision that attempts to prohibit or unreasonably restrict ADU construction.

If there is a conflict between HOA governing documents and state law, state law controls.

How This Works in Practice

1. The homeowner designs an ADU that complies with state and local zoning laws.
2. The HOA may review for design compliance only.
3. Any HOA rule that directly contradicts state ADU law is unenforceable.

Quick Answers

• What if my CC&Rs say “no secondary units”? That provision is void under California law.
• Can my HOA deny my ADU based on old governing documents? No, outdated restrictions that conflict with state law cannot be enforced.
• Does the city require HOA approval before issuing permits? No. Permit approval is ministerial and separate from HOA review.

How Many ADUs Can You Build on One Property in California?

California law allows multiple ADUs on certain properties, depending on zoning and lot type. This means some properties may support up to three total units (primary residence + ADU + JADU). HOAs cannot reduce the number of ADUs allowed under state law.

Quick Answers

• Can an HOA limit me to only one ADU? No, if state law allows more.
• Do all cities allow multiple ADUs? Rules vary slightly, but state minimum allowances apply.
• Can I build two detached ADUs? Not on most single-family lots.

For most single-family lots, you may build:

Types of Restrictions HOAs Can Legally Enforce

AB 670 and Civil Code Section 4751 ensure that homeowners maintain the right to build an ADU in their backyard, but they don’t take all power away from HOAs. HOAs still have the right to enforce certain rules.

While “enforcement” doesn’t allow them to prevent ADU construction, it does allow them to fine homeowners on a monthly basis for having an ADU on their property that defies certain rules when it comes to exterior design and overall aesthetics.

HOAs can enforce reasonable design and setback restrictions but must align with state laws.

Permissible HOA Rules

Permissible HOA rules that can be enforced with fines include:

Design & paint color. HOAs can require that any ADUs be designed in a way that complements the design of the neighboring houses. It can also require certain paint colors or roofing to be used.

Landscaping design. As with primary dwellings, HOAs can set certain standards when it comes to the landscaping of ADUs.

Maintaining certain sight lines. If the association has shared common spaces, like pools or parks, they can require that an ADU not obstruct community views. Maintaining noise and privacy standards. The addition of an ADU isn’t allowed to violate community living standards set forth by the HOA, particularly when it comes to overall noise levels and privacy. For noise, this may mean scheduling construction to fall outside of any designated “quiet hours.”

Reasonableness Requirement

By California law, the above restrictions are all considered “reasonable” because they don’t impede ADU construction and can be achieved by a homeowner without much additional cost. In fact, if you live in an HOA, you’ll notice that many of these provisions are ones you already follow in your single-family home.
Essentially, HOAs maintain the right to enforce the same aesthetic requirements for ADUs as they do for primary dwellings.

What Restrictions Can an HOA Place on an ADU?

While an HOA cannot prohibit an ADU that complies with California law, it may impose reasonable restrictions related to exterior appearance and community standards. These restrictions must be objective and cannot make construction financially or physically impossible.

Examples of Permissible HOA Restrictions

• Architectural style must match the primary residence
• Specific paint colors or roofing materials
• Height limits consistent with neighborhood standards
• Landscaping requirements
• Placement rules that comply with the state’s 4-foot side and rear setback allowance

Restrictions That Are Not Allowed

• Outright bans on ADUs
• Setbacks greater than what state law allows (beyond 4 feet side/rear)
• Excessive design requirements that dramatically increase cost
• Requiring parking replacement for a converted garage (if state law exempts it)

Quick Answers

• Can an HOA require my ADU to match my house? Yes. HOAs may require exterior design consistency, as long as it’s reasonable.
• Can an HOA impose stricter setbacks than the city? No. HOA setback rules cannot conflict with California’s minimum ADU allowances.
• Can an HOA limit the size of my ADU? They may impose size limits, but not in a way that prevents you from building a legally allowed unit.
• Can an HOA require specific materials? Yes, if the requirements are objective and consistent with community standards.

Parking and Garage Conversion Rules for ADUs in HOA Communities

State law limits when parking can be required for ADUs. In many cases, no additional parking is required, especially for garage conversions. HOAs cannot override state parking exemptions.

When Parking Is Typically Not Required

• ADU is within a transit priority area
• ADU is created by converting an existing garage
• Property is near public transportation

Quick Answers

• Can my HOA require me to replace a converted garage parking space? No, if state law exempts the requirement.
• Can they require guest parking spaces? Only if applied uniformly and not in conflict with state law.
• Does street parking factor into approval? HOAs may regulate community parking rules but cannot block ADU construction over parking concerns alone.

Do You Need HOA Approval to Build an ADU?

Even though an HOA cannot prohibit your ADU, most associations still require design review approval before construction begins. This review focuses on aesthetics and exterior standards, not your legal right to build.

Typical HOA Approval Process

1. Submit architectural drawings to the HOA design review committee.
2. Provide material and finish selections.
3. Receive written approval or revision requests.

Failure to obtain design approval may result in fines, even if the ADU itself is legal.

Quick Answers

• Can I skip HOA approval if state law allows ADUs? No. You must still comply with procedural design review rules.
• Can the HOA delay my project indefinitely? No. They must act reasonably and within their own review timelines.
• Can I build first and deal with the HOA later? Doing so may result in fines or enforcement action.

Navigating HOA Guidelines for ADU Construction

Before beginning any ADU project within an HOA-governed neighborhood, review your HOA governing documents to understand the restrictions that might be in place when it comes to ADU design. It’s much easier and more cost-effective to design with these restrictions in mind than to have to modify your plans after you’ve already begun the permitting process.

Understanding HOA bylaws and planning in advance saves time and avoids costly revisions during construction.

Reviewing HOA Governing Documents

As an HOA member, you had to sign certain documents before you moved in. These documents outlined any HOA fee structures and bylaws, as well as any Covenants, Conditions, and Restrictions (CC&Rs). It’s in the CC&Rs that you’ll find any restrictions your HOA has outlined when it comes to ADUs.

Seek HOA Approval (When Necessary)

While you as a homeowner have the right to build an ADU regardless of your HOA’s rules, it’s still a smart idea to get your design plans approved by your HOA before you build. It’s a good idea for two reasons: First, it ensures that you read your HOA’s governing documents correctly and won’t incur any fines after the ADU construction is completed. These fines can be billed monthly until modifications are made to bring your ADU up to community standards. Second, getting your design plans approved by your HOA maintains strong community relations, which is essential for maintaining quality of life as an HOA member.

Consulting with Experts

While pre approved plans are readily available online for little or no cost, they may need to be modified to meet your HOA’s standards. This is where an ADU professional like Better Place can help. We help homeowners not only understand and navigate their city’s ordinances but their HOA’s, too, to ensure a smooth construction process from start to finish.

Work with ADU professionals to navigate HOA standards and ensure a seamless construction process that aligns with all regulations.

What to Do if an HOA Blocks Your ADU Project

Legally, an HOA can’t block your ADU project. If an HOA tries to do so or informs you that your ADU design violates community standards, you have 2 courses of action: You can modify your ADU plans to meet community preferences, or you can challenge an unreasonable restriction.

If your HOA blocks your ADU, consult legal experts to challenge unreasonable restrictions under California law.

Challenging Unreasonable Restrictions

If an HOA rejects your current ADU plans due to a restriction you feel is unreasonable (meaning it goes against city or state laws or places an undue burden on your budget or the construction process), you can challenge these restrictions in court. This typically requires consultation with a real estate lawyer.

Alternative Solutions

If an HOA rejects your ADU plans due to its failure to comply with certain setback limits or height limits, this is within their right, and in order to get your plans approved, you must modify them to comply with community standards.

What You Should Know About Building an ADU in Condominiums

Building an ADU or JADU in a condo complex can be more complicated than building in a neighborhood of single-family houses, as condos often share walls, utilities, and other systems that can make building an individual ADU complicated.

While it isn’t always impossible to build an ADU in these situations, it’s something that requires the consultation of your city building department, your HOA, and an ADU expert to see if it’s viable.

Condo ADUs often face additional hurdles due to shared systems and space—consult experts early to assess feasibility.

Work with Experts Like Better Place Design & Build

At Better Place Design & Build, we’re experts at helping homeowners not only design an ADU that meets all their personal requirements, but also those of the state, city, and homeowners association. See what’s possible in your backyard, no matter what kind of restrictions might be in place, by scheduling a free consultation.