The landscape for accessory dwelling unit (ADU) construction in California has evolved significantly in favor of homeowners. As of 2025, the California Department of Housing and Community Development’s ADU Handbook outlines robust protections for homeowners seeking to build ADUs, particularly against restrictive Homeowners Association (HOA) policies. These guidelines reflect California’s commitment to facilitating ADU development as a crucial strategy for addressing the state’s housing needs.

If you’re considering building an ADU and belong to an HOA, you might wonder about potential restrictions or requirements. Here’s what you need to know about your rights and the limits of HOA authority over ADU construction.

The fundamental principle is clear: HOAs cannot prevent you from building an ADU on your property if it’s zoned for single-family residential use. California law explicitly states that any covenants, conditions, and restrictions (CC&Rs) that effectively prohibit or unreasonably restrict ADU construction are void and unenforceable.

This protection extends beyond just construction rights. HOAs cannot prohibit you from renting your ADU, and state law mandates that at least 25 percent of units within a common interest development must be allowed as rental properties. This provision ensures that ADUs can fulfill their intended role in expanding housing availability.

While HOAs retain some authority to maintain community standards, their power is strictly limited when it comes to ADUs. They can establish certain objective standards, such as specific materials or architectural styles, but these requirements must meet several key criteria.

First, any standards must be reasonable and cannot be more restrictive than state law. For example, if state law permits ADUs with four-foot setbacks, an HOA cannot mandate larger setbacks. Similarly, if state law allows 800-square-foot ADUs, an HOA cannot impose a smaller maximum size requirement.

Second, HOA requirements cannot unreasonably increase construction costs or create de facto prohibitions on ADU development. This means HOAs cannot impose excessive fees, maintenance requirements, or design standards that would make ADU construction financially unfeasible.

A crucial aspect of California’s ADU laws concerns the approval process itself. HOAs are explicitly prohibited from influencing local agency approval of ADUs. The law requires a ministerial, objective approval process free from discretionary review or third-party input.

This means your local agency can not:

If a local agency attempts to incorporate HOA input into their approval process, they are in violation of state law.

State law prohibits HOAs from imposing restrictions that aren’t objective or readily available to property owners before application submission. They cannot require owner occupancy of ADUs or charge excessive maintenance fees. HOAs also cannot mandate parking requirements for properties where state law exempts ADUs from such requirements, like one located within half a mile of public transit.

HOAs are limited to establishing reasonable, objective standards that align with state law. These might include:

If you encounter resistance from your HOA regarding ADU construction, you have clear recourse under state law. Property owners whose ADU projects face HOA interference should contact their local agency and consider seeking legal counsel. Remember, any HOA rules that contradict state ADU law are automatically void and unenforceable.

California’s ADU laws represent a clear policy direction: facilitating the development of these crucial housing units by removing unnecessary barriers. The state has systematically limited HOA authority to restrict ADU development, creating a more straightforward path for homeowners who wish to build these units. While HOAs maintain some authority to ensure community standards, their power cannot override the state’s commitment to expanding housing options through ADU development.

That these protections stem from carefully crafted state policy designed to address California’s housing needs. As you plan your ADU project, you can move forward knowing that the law stands firmly on the side of responsible ADU development, regardless of HOA restrictions that might suggest otherwise.

If you’re looking to build an ADU, Samara makes it easy. We handle everything from permits to installation, and even offer our own financing. Call us at 650-420-2607 to schedule a 15-minute consultation and discover how simple adding a Backyard ADU can be.

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