The short answer: Whether an HOA can block an ADU depends on the state, and the reason is simple: a zoning law that allows ADUs does not automatically cancel the private covenants (CC&Rs) of your homeowners association. An HOA is bound by state law only where the legislature has specifically limited what covenants can say. California, Colorado and, from 2027, Oregon have such limits. In most other states, your HOA’s governing documents can still prohibit an ADU even though the city would approve it.
Last verified: October 2, 2026 ยท Written by the ADU Scope editorial team
Attention: Cities and HOAs are separate. A building permit from your city does not mean your HOA will allow the project, and an HOA approval does not mean the city will issue a permit. In states without an HOA override, you need both.
Can an HOA block an ADU when zoning allows it?
Zoning is public law that regulates what a city permits on your lot. CC&Rs are a private contract that you accepted when you bought into the community, and courts generally enforce them as written. When a state passes a law saying cities must allow ADUs, it changes the first set of rules. It leaves the second set alone unless the statute says otherwise.
This is why the question “Can I build an ADU?” has two separate answers: one from the city and one from the HOA. Many owners discover the second only after hiring a designer.
Where to find your HOA rules
- Declaration of CC&Rs, recorded with the county and usually in your closing documents.
- Bylaws and rules, which cover procedures and architectural review.
- Architectural review committee guidelines, which often add standards for materials, height and appearance.
Read all three. A declaration that is silent on ADUs may still ban “additional dwellings” or “rental units” in other language, so search for terms like “single-family,” “accessory,” “outbuilding” and “rental.”
Tip: Ask the HOA for its full governing documents in writing and keep the dated response. If a dispute arises later, you will want proof of what the HOA said and when.
California: can an HOA block an ADU under Civil Code 4751?
California has the strongest protection. Civil Code section 4751 says governing documents “may not include any provision” that “effectively prohibits or unreasonably restricts the construction or use of an accessory dwelling unit or junior accessory dwelling unit on a lot zoned for single-family residential use.” Restrictions that do not unreasonably increase cost or effectively prohibit construction can survive.
What this means in practice
- A blanket ban on ADUs in the CC&Rs is void.
- Reasonable rules about appearance or placement may remain, as long as they do not make building impractical or unreasonably costly.
- The HOA cannot use its approval process to block a ministerially approved ADU.
There is an important caveat. A San Diego County Superior Court ruling in early April 2026 (Hardesty v. Mystic Point Homeowners Association), involving a condominium in Carlsbad, went against the owner who relied on section 4751. As reported, the court reasoned that the 2019 law does not cover condominium developments and applies only to lots zoned for single-family residential use. The ruling was covered by CalMatters, KPBS, Times of San Diego and inewsource, but we have not reviewed the court order itself. A trial-court decision is not binding on other courts, and we found no record of an appeal or final judgment, but it shows that condo owners should not assume the protection applies to them.
Attention: If you live in a condominium or in a development with mixed zoning in California, get a written legal opinion before spending money on plans.
Colorado and Oregon: can an HOA block an ADU?
Colorado. According to a Colorado community-association law firm, HB24-1152 made it unlawful for associations in ADU-supportive or subject jurisdictions to prohibit owners of single-family detached homes from building ADUs on their lots. Associations can still enforce restrictions that do not unreasonably increase construction cost, do not effectively prohibit construction, and do not extinguish the ability to otherwise build one. Setback and architectural covenants may therefore still apply. Check whether your town is a subject or supportive jurisdiction first (see our Colorado article).
Oregon. HB 2138, signed in July 2025, makes certain private covenants that prohibit or unreasonably restrict middle housing, ADUs or housing density void and unenforceable. The provisions apply retroactively to existing governing documents. A law-firm summary reports a general effective date of January 1, 2027, with rulemaking deadlines in 2028, so the practical effect may depend on timing and on details still being defined. Confirm the effective date of the HOA provisions before relying on them.
| State | HOA protection for ADUs | Main limit |
|---|---|---|
| California | Yes, Civil Code 4751 | Reasonable restrictions survive; condo coverage questioned in a 2026 trial-court ruling |
| Colorado | Yes, under HB24-1152 | Only in subject or supportive jurisdictions; single-family detached homes |
| Oregon | Yes, under HB 2138 | Effective date and details still being implemented |
| Other states | Not confirmed here | Check state statute and your documents |
Washington, Arizona and Everywhere Else
Washington’s ADU statutes (RCW 36.70A.680 and .681) restrict what cities and counties can do. I did not find confirmation that they void private HOA covenants, so do not assume they do. The same applies to Arizona’s 2024 statute (HB 2720), which also addresses local governments. In both states, treat your HOA documents as binding until a lawyer tells you otherwise.
One source I reviewed claims California is the only state that bars HOAs from banning ADUs outright. That is outdated if the Colorado and Oregon provisions above work as described, so be cautious with any “only state” claim you read online.
What to do if your state offers no HOA protection
- Read the CC&Rs for any ban on additional dwellings or rentals.
- Ask the architectural committee for its written standards.
- Request a variance or an amendment; many covenants can be changed by a vote.
- Consider a unit type the covenants may allow, such as an interior conversion.
- Consult a community-association attorney before design spending.
What to Do If Your HOA Blocks an ADU
If your HOA denies a project that state law protects, the order of steps matters. Start by sending the HOA a written request that cites the statute. Many boards back down once they see that their documents conflict with state law. If they do not, an attorney letter is the next step, followed by mediation or a court action. Some states award attorney fees to the prevailing party, which can change the economics of a dispute, so check your state’s rules.
Keep the city process moving in parallel. The city approves the building permit regardless of what the HOA says, and in California the HOA cannot influence ministerial approval or charge fees as a condition.
Frequently Asked Questions
Can an HOA ban ADUs in California?
Not by a blanket rule. Civil Code 4751 voids provisions that effectively prohibit or unreasonably restrict ADUs on single-family lots, though condo situations are less clear.
Does a state ADU law override my HOA?
Only if the statute says so. Many state ADU laws regulate cities, not private covenants.
Can the HOA still require design approval?
In states with protection, reasonable standards may remain if they do not unreasonably raise cost or block construction.
What if my HOA documents are silent on ADUs?
Check for related language on additional dwellings, rentals and outbuildings. Silence is not always permission.
Next Steps
- Colorado ADU Law 2026: What HB24-1152 Means for Homeowners
- California ADU Laws 2026: What Changed and What You Can Build
- ADU Laws by State: Where You Can Build in 2026
- Can You Sell an ADU Separately? California AB 1033 Explained
- ADU Setback Requirements Explained: California, Washington, Colorado and Portland
General information, not legal advice. Local rules vary and change; confirm with your planning department and a licensed attorney.
Sources: HOA Management: ADUs in HOAs ยท Altitude Community Law: ADUs Are Here to Stay ยท Mondaq: Oregon HB 2138 ยท Oregon Enrolled HB 2138 ยท Pacific Beach Builder: report on the Carlsbad ruling ยท HCD ADU Handbook, March 2026 ยท CalMatters: HOA and ADU ruling in Carlsbad (April 2026) ยท KPBS: California HOA triumphs over ADU law