Key Takeaways:
- HOAs cannot legally prohibit ADU construction if your project complies with California state laws like AB 670, AB 3182, and Civil Code 4751.
- Reasonable HOA restrictions are allowed (e.g., matching design or setbacks) but cannot make your ADU project unfeasible or excessively costly.
- HOAs cannot enforce owner-occupancy rules or deny rentals for ADUs, except in cases involving Junior ADUs (JADUs) or short-term rentals under 30 days.
- If an HOA unfairly denies your ADU, you have legal rights—seek written justification and consider professional or legal help to challenge the decision.
Understanding Accessory Dwelling Units (ADUs) and Homeowners Associations (HOAs)
An Accessory Dwelling Unit (ADU) is a smaller, independent living space located on the same property as a primary home. Often called granny flats, in-law units, or guest houses, ADUs must include essential living facilities such as a kitchen, bathroom, and sleeping area, providing a complete and separate dwelling for one or more people. ADUs are popular in California because they offer flexible housing options, can increase property value, and provide potential rental income.
A Homeowners Association (HOA) is an organization that creates and enforces rules for residential communities like subdivisions, planned developments, or condominium buildings. HOAs aim to maintain community standards, protect property values, and manage shared amenities. Residents in HOA-governed communities typically agree to follow these rules and pay fees that cover the maintenance of common areas.
California Laws Protecting Your Right to Build an ADU
California law generally prohibits Homeowners Associations (HOAs) from outright blocking the construction of Accessory Dwelling Units (ADUs). This is a result of recent legislation designed to increase the housing supply and address the state’s housing crisis. Key laws, such as AB 3182, AB 670, and Civil Code Section 4751, prevent HOAs from enacting or enforcing rules that “effectively prohibit or unreasonably restrict” the building or rental of ADUs or Junior Accessory Dwelling Units (JADUs). This means that any HOA guideline that makes ADU construction so challenging it cannot realistically be completed is invalid.Â
Furthermore, these laws protect a property owner’s ability to rent out their ADU or any other part of their property, making it difficult for HOAs to limit rentals. While HOAs cannot prevent ADUs, they can impose reasonable restrictions, though what is “reasonable” is often still being defined in city rules and courts.
What “Reasonable Restrictions” Mean for Your ADU
While California law prevents HOAs from prohibiting ADU construction, it does permit them to impose “reasonable restrictions.” These restrictions are typically aimed at maintaining the community’s overall appearance and standards and must not add significant expense or time to the construction process. Common reasonable restrictions often relate to aesthetics, such as requiring the ADU’s design, materials, and color (like windows, stucco, and roofing) to match the main house or the general neighborhood appearance. HOAs can also require specific setback distances, though these cannot be stricter than 4 feet from the side and rear property lines.Â
Some HOAs may request the installation of “story poles” to visualize the ADU’s footprint and height during the planning phase, which is generally considered a reasonable request, usually costing between $2,000 and $4,000. HOAs can also set height limits, but these must align with state law, which allows detached ADUs up to 16 feet in most cases, and up to 18 feet in specific circumstances. For attached ADUs, height can be up to 25 feet if attached to the primary dwelling. They can also enforce community standards regarding landscaping, noise levels, and privacy. However, these reasonable restrictions cannot be so burdensome that they make the project financially unfeasible or effectively impossible to build.
What HOAs Cannot Do When It Comes to ADUs
California law significantly limits the power of Homeowners Associations (HOAs) to restrict Accessory Dwelling Unit (ADU) construction. HOAs cannot outright ban ADU or Junior Accessory Dwelling Unit (JADU) projects on single-family residential lots. They are also prohibited from imposing restrictions that “unreasonably restrict” or have the “effect of prohibiting” ADU construction or rental. This means HOAs cannot create rules that significantly increase project costs, cause substantial delays, or effectively extinguish the ability to construct an ADU.
Specifically, HOAs cannot impose stricter size limitations than allowed by state law; for instance, they cannot mandate an ADU smaller than 850 square feet for a one-bedroom unit or 1,000 square feet for a two-bedroom unit if state law permits larger sizes. Similarly, they cannot require setback distances greater than 4 feet from side and rear property lines. While HOAs can regulate aesthetics, they cannot block ADUs based on arbitrary design concerns or require design elements that are not required by law.
Furthermore, California law makes it easier for homeowners to use their ADUs as rental units without significant HOA interference, although HOAs may be able to ban short-term rentals under 30 days. HOAs cannot require owner occupancy for ADUs, except for Junior ADUs (JADUs), as this restriction was permanently removed for ADUs by AB 976. HOAs are also forbidden from requiring HOA approval as a prerequisite for obtaining building permits from the city, and local agencies are not permitted to involve HOAs in the ADU application or review process. This ensures that the city’s approval process remains ministerial, meaning it is based on objective standards rather than subjective review.
Navigating the ADU Approval Process with Your HOA
To ensure a smooth ADU project within an HOA-governed community, homeowners should follow a strategic approach. The first crucial step is to carefully review your HOA’s Covenants, Conditions & Restrictions (CC&Rs). These documents outline the community’s guidelines and potential restrictions related to design, materials, and placement of structures. It is advisable to have an ADU design expert review these documents, as some HOA requirements may be invalidated by state and local ADU laws.
When submitting plans, homeowners can use the same architectural plans for both the HOA and the city building department. There are two main approaches for submission: concurrent submission to both the HOA and the municipality, which can save time but carries the risk of needing to revise city-submitted plans if the HOA requests changes; or submitting to the HOA first, then the city, which allows for HOA feedback to be incorporated upfront, potentially preventing conflicts but possibly extending the overall timeline.
Homeowners should anticipate that their HOA may request revisions to the plans, typically related to aesthetic elements to ensure the ADU matches the main residence and neighborhood. These design adjustments can often be handled efficiently during the plan revision process required by the municipality. While HOAs generally do not review structural plans, finalizing as many design selections as possible before submission can help minimize delays. HOAs are expected to respond within a timeline similar to the city, typically not more than 60 days, and if they fail to approve or deny within the specified timeframe, the application may be deemed approved. Maintaining clear and ongoing communication with both the homeowners and the HOA is essential to ensure design plans meet all requirements and revisions are handled promptly.
 What to Do if Your HOA Tries to Block Your ADU Project
If your Homeowners Association (HOA) attempts to block or unreasonably restrict your Accessory Dwelling Unit (ADU) project in California, several steps can be taken to protect your rights. First, it is crucial to thoroughly understand California’s ADU laws and how they limit HOA authority. These laws ensure that HOAs cannot outright ban ADUs or impose rules that effectively make construction impossible or excessively costly.
If your HOA denies your plans, request a written justification for the denial, including references to specific governing documents or state laws they are citing. Often, disputes arise because HOA rules appear to contradict state laws, particularly concerning design requirements, size, appearance, parking, and landscaping.
If the HOA’s restrictions seem unreasonable or violate state law, consider consulting with an ADU expert or a real estate attorney specializing in HOA disputes. An experienced professional can evaluate whether the restrictions are legally enforceable and advise on potential legal remedies. They can help advocate on your behalf, negotiate with the HOA board, and challenge actions that go beyond what state law permits.
Homeowners can formally challenge the HOA’s decision through internal processes, demand letters, or, if necessary, legal action. Litigation may be required if the HOA continuously ignores state laws, applies rules selectively, improperly amends governing documents to restrict ADUs, or causes indefinite delays without justification. While modifying your plans to meet reasonable HOA standards might be the quickest and least expensive path (typically $2,000–$4,000 for adjustments like story poles), homeowners have the right to seek legal action against an HOA board that is imposing unreasonable guidelines. Legal counsel can help homeowners pursue remedies and ensure their ADU project moves forward in compliance with state law.
Common Concerns About Building ADUs in HOA Communities
Homeowners often have several common questions and concerns when considering building Accessory Dwelling Units (ADUs) within communities managed by Homeowners Associations (HOAs) in California. A primary concern is whether their HOA can completely prevent them from constructing an ADU, despite state laws designed to promote ADU development. Many homeowners also worry about the specific types of restrictions an HOA can legally impose on ADUs, particularly concerning design elements, size limitations, and setback requirements. They are concerned that these restrictions might add significant costs or cause delays to their project.
Another frequently asked question revolves around the approval process itself: how long it takes, whether HOA approval is required alongside city permits, and the potential for conflicts between HOA rules and municipal regulations. Homeowners also seek clarification on whether HOAs can impose rules that limit the rental use of an ADU, such as requiring owner occupancy or prohibiting rentals altogether. There are also questions about the financial aspects, such as whether HOAs can charge additional fees for ADU approval and if these fees are reasonable.
Concerns also extend to the complexities of building ADUs in condominium communities due to shared walls, utilities, and common spaces, which can lead to legal ambiguities and require collective authorization from other condo owners. Finally, homeowners want to understand their rights and the steps to take if an HOA attempts to impose unreasonable restrictions or outright denies their ADU plans, including when to seek legal guidance. These concerns collectively highlight the need for clear information on HOA authority, homeowner rights, and effective strategies for navigating the ADU construction process in California’s HOA communities.
FAQ
Can my HOA completely prevent me from building an ADU in California?
No, HOAs cannot completely stop you if your ADU complies with California state law.
What kinds of restrictions can an HOA impose on ADUs?
They can set reasonable rules for design, size, and placement, but not block your project outright.
Do I need HOA approval in addition to city permits?
Yes, usually you need both.
Can an HOA restrict rental use of an ADU?
They can try, but any rules must follow state law.
Can HOAs charge fees for ADU approval?
Yes, but the fees must be reasonable.
Are there extra issues for ADUs in condos?
Yes, because of shared walls and spaces. You may need other owners’ or the board’s approval.
What if my HOA unfairly denies my ADU request?
Know your legal rights and consult a lawyer if needed.
Learn More About Building ADU
Curious about ADU permits, costs, or the latest 2025 law changes? Dive deeper into Accessory Dwelling Units with these helpful guides:
How Long Does it Take to Build an Accessory Dwelling Unit (ADU)
How Much Does it Cost to Build an ADU
What is the New ADU Law 2025?
How Much is a Permit to Build an ADU in California?
How to Get ADU Permit California
What is a State Exempt from ADU?
Can My ADU Be Bigger Than My House?
How Much Value Does an ADU Add to a Property in California?
How Many Bedrooms Can an ADU Have in California
Learn everything you need to plan smart, save money, and maximize the value of your ADU investment.
