AB 956 Explained: Could California Homeowners Build Two Detached ADUs?

Accessory dwelling units have already transformed the way Californians think about their properties.

A backyard that once represented unused space can now potentially become a rental, guest house, home for an aging parent or residence for an adult child.

California may be preparing to expand those possibilities again.

AB 956 has passed the California Legislature and, as of September 25, 2026, is awaiting action by Governor Gavin Newsom. The proposal would generally increase the number of detached new-construction ADUs that must receive ministerial approval on qualifying single-family properties from one to two.

What is AB 956?

California law already gives many homeowners the right to build an accessory dwelling unit, subject to statewide and local standards.

AB 956 would expand that framework.

For qualifying lots containing a proposed or existing single-family dwelling, local governments would generally be required to ministerially approve as many as two detached new-construction ADUs, subject to applicable standards.

"Ministerial" is important.

It generally means an application that meets objective requirements can be approved without the discretionary hearings traditionally associated with many development applications.

Does AB 956 mean everyone can build two ADUs?

No.

The legislation expands statewide rights, but the physical property still matters.

Feasibility can depend on issues including:

• Lot size and configuration
• Existing structures
• Setbacks
• Fire access
• Utilities
• Sewer or septic capacity
• Coastal requirements
• Building codes
• Easements
• Topography
• Other objective development standards

Before making financial decisions based on ADU potential, homeowners should have the property evaluated by appropriate planning, design and construction professionals.

Why would someone want two ADUs?

This is where AB 956 becomes particularly interesting for established homeowners.

Two ADUs could create several possibilities.

Multigenerational living: One unit could accommodate an aging parent while another eventually houses an adult child.

Rental income: Owners could potentially create additional long-term rental income, subject to applicable laws and local rules.

Caregiver housing: An ADU can allow a caregiver to live nearby without sharing the primary residence.

Future downsizing: Some homeowners may eventually prefer living in a smaller unit while retaining flexibility with the primary residence.

Estate planning: Additional housing can provide families with options as needs change across generations.

Could two ADUs increase property value?

Potentially — but value isn't simply the construction cost plus the amount spent on the ADUs.

An appraiser or buyer may consider:

• Rental income potential
• Quality of construction
• Privacy
• Parking
• Layout
• Lot usability
• Effect on the main home's outdoor space
• Comparable properties
• Local demand

Poorly planned ADUs can also make a property feel crowded or reduce desirable yard space.

For that reason, maximizing the number of units isn't always the same thing as maximizing property value.

Why is this relevant in Orange County?

Orange County has many established neighborhoods where buying additional land is extraordinarily expensive.

That makes better use of existing residential land increasingly valuable.

For families in Newport Beach, Irvine and surrounding communities, an ADU may offer an alternative to:

• Paying for assisted living
• Helping an adult child purchase another property
• Moving to accommodate multigenerational needs
• Buying a separate investment property

The economics are highly property-specific, but the flexibility can be valuable.

What about HOAs?

AB 956 also addresses restrictions involving common-interest developments and ADUs.

Homeowners in HOA communities should still review their governing documents and obtain current legal or planning guidance rather than assuming statewide legislation eliminates every design or construction requirement.

Has AB 956 become law?

Not yet.

The Legislature passed the bill, and it was presented to the governor on September 4. As of September 25, it remains pending.

That means homeowners should not make construction decisions based on the assumption that the proposed two-ADU standard is already effective.

The bottom line

AB 956 represents another step in California's transition from thinking of a single-family property as necessarily containing only one home.

For homeowners, the most interesting question may no longer be:

"How much is my house worth?"

It may also be:

"What could this property become over the next 10 or 20 years?"

For families thinking about rental income, multigenerational living, aging in place or long-term flexibility, that question is becoming increasingly important.