California AB 956: New Law Allows Two Detached ADUs on Single-Family Lots
California is continuing to expand opportunities for homeowners to build accessory dwelling units. One of the latest changes is Assembly Bill 956 (AB 956), which significantly expands the number of detached ADUs that may qualify for streamlined approval on a property with a single-family home.
On September 29, 2026, Governor Gavin Newsom announced the signing of AB 956 as part of a larger package of California housing legislation.
For homeowners, considering an ADU in Los Angeles, Pasadena, Altadena, Burbank, Glendale, Culver City, or elsewhere in Southern California, this could create new opportunities to add housing, accommodate family members, or generate rental income.
Here is what homeowners need to know.
What Is AB 956?
AB 956 modifies California Government Code Section 66323, which establishes certain categories of ADUs that cities and counties must approve through a ministerial process when the project meets state requirements.
Previously, this section of state law required local agencies to allow one detached, new-construction ADU on a property with an existing or proposed single-family residence.
AB 956 changes that number from one detached ADU to two detached ADUs.
The final enrolled legislation states that local agencies must ministerially approve:
“Two detached, new construction, accessory dwelling units” on a lot with an existing or proposed single-family dwelling, subject to the requirements contained in the statute.
In practical terms, qualifying homeowners may soon have the ability to construct two separate detached ADUs in addition to their primary residence.
When Does AB 956 Take Effect?
AB 956 is a non-urgency bill passed during California's regular legislative session.
California law generally provides that regular-session statutes take effect on January 1 of the following year, unless the legislation specifies another effective date.
That means AB 956 is scheduled to take effect:
January 1, 2027
Homeowners who are considering multiple ADUs may want to begin evaluating their properties, design options, utility requirements, and construction budgets before the new rules become operative.
How Large Can the Two Detached ADUs Be?
Under the streamlined provisions amended by AB 956, a local agency may impose a floor-area limitation of not more than 800 square feet of livable space on each detached new-construction ADU.
That could potentially mean:
For example, a homeowner with sufficient usable lot area could potentially build two separate 800-square-foot ADUs, creating approximately 1,600 square feet of additional residential space.
However, every property is different. Lot configuration, fire access, utility locations, easements, grading, building-code requirements, and other site conditions can affect what can actually be constructed.
What Are the Setbacks?
AB 956 retains the state-law standard allowing the two qualifying detached ADUs to have:
Up to a 4-foot side-yard setback and 4-foot rear-yard setback.
The enacted language specifically applies to two detached new-construction ADUs that do not exceed four-foot side and rear setbacks.
This is particularly important in Los Angeles, where many properties have limited backyard space.
It does not, however, mean that every portion of every lot can automatically be developed. Other building, fire-safety, utility, easement, and site-specific requirements may still affect the location and design of the structures.
Can You Have a Main House and Two Detached ADUs?
Under the new state-law provision, yes, qualifying properties with an existing or proposed single-family residence may be eligible for:
1 Primary Residence + 2 Detached ADUs
That creates the possibility of three separate dwelling units on a traditional single-family property through this particular state ADU pathway.
Depending on the existing structures and the specific ADU configuration, other state ADU provisions may also apply.
What About a Garage Conversion or Conversion ADU?
This is where AB 956 becomes particularly interesting.
Government Code Section 66323 allows certain categories of ADUs to be approved individually or in combination, subject to the exceptions contained in the statute. The law separately addresses an ADU created within qualifying existing space as well as the detached new-construction ADUs.
This means some properties may potentially qualify for configurations involving an existing-space or garage-conversion ADU together with detached ADUs.
However, homeowners should not assume that every property automatically qualifies for the maximum theoretical number of units. The existing structures, previous ADU approvals, zoning, site conditions, and exact permitting pathway should be reviewed before design begins.
What About a Junior ADU?
AB 956 includes an important limitation concerning Junior Accessory Dwelling Units, or JADUs.
The legislation states that a local agency is not required to ministerially approve a new JADU on a lot where two detached new-construction ADUs have already been constructed under this provision.
Therefore, homeowners considering a combination of detached ADUs, conversion ADUs, and a JADU should have the property and permitting strategy evaluated carefully before deciding which units to build.
The sequence and type of ADUs can matter.
AB 956 Also Changes HOA Restrictions
AB 956 addresses more than the number of ADUs.
California law already limits the ability of certain private covenants and homeowners associations to prohibit or unreasonably restrict legally permitted ADUs.
AB 956 changes the statutory wording from property “zoned for single-family residential use” to property “zoned to allow single-family residential use.”
This expands the language of the protection to properties where single-family residential use is allowed even if the underlying zoning designation is not exclusively single-family.
Reasonable restrictions may still apply, but they cannot effectively prohibit an ADU that is protected under state law.
Does AB 956 Mean Every Property Can Have Two ADUs?
No.
AB 956 expands the state ADU approval pathway, but it does not eliminate the normal technical requirements involved in constructing a residential building.
Before assuming two detached ADUs can be built, the property should be evaluated for issues such as:
Available buildable area
Existing structures
Property setbacks
Easements
Utility locations and capacity
Sewer or septic conditions
Electrical service
Fire access and fire-safety requirements
Hillside or grading conditions
Flood or geological conditions
Coastal requirements where applicable
Building-code requirements
Existing unpermitted construction
A good ADU feasibility study should examine these issues before architectural and engineering plans are completed.
What AB 956 Could Mean for Los Angeles Homeowners
For homeowners with larger lots, AB 956 may create substantially more flexibility.
Consider a Los Angeles property with a large backyard.
Under the new law, a possible concept might be:
Existing House
↓
Detached ADU #1 — 800 SF
↓
Detached ADU #2 — 800 SF
Instead of constructing one larger ADU, some property owners may choose two smaller independent homes.
This type of configuration could be useful for:
Multigenerational living — One ADU for parents and another for adult children.
Rental income — Two independent rental units rather than one.
Long-term property planning — Additional residential units can give owners more options as family and housing needs change.
Housing flexibility — Owners may be able to create smaller residential units while retaining the existing primary home.
The best configuration will depend on the property's dimensions, existing improvements, utilities, construction cost, and the homeowner's goals.
Thinking About Building Two ADUs?
The first step should not necessarily be drawing plans.
The first step is determining what the property can realistically support.
At Centrepoint Construction Inc., we provide design-build services for accessory dwelling units throughout Los Angeles and surrounding communities. Our team can evaluate the property, review potential ADU configurations, coordinate architectural and engineering plans, navigate the permitting process, and construct the project from foundation through final inspection.
For homeowners considering taking advantage of California's new AB 956 rules, starting the feasibility and design process early can help identify potential obstacles before significant money is invested in plans.
Planning an ADU in Los Angeles?
If you are considering:
One detached ADU
Two detached ADUs
A garage conversion
An ADU addition
Multiple ADUs on a larger property
A new-construction ADU
An ADU as part of a larger home renovation
Centrepoint Construction Inc. can help determine which approach makes the most sense for your property.
Contact Centrepoint Construction to schedule an ADU property evaluation and feasibility consultation.
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