Two Detached ADUs Instead of One: What AB 956 Could Mean for Your Los Angeles Lot

By Lior Mazor, Hillstar Construction Inc · October 31, 2026

California homeowners may have a new ADU option they may not realize is coming: on a qualifying single-family property, AB 956 can allow two new detached ADUs instead of one.

Concept illustration, not a Hillstar project.

It's a real change, though not in effect yet, and it comes with real conditions. "Qualifying" is doing a lot of work in that sentence, and the City of Los Angeles has not yet said how it will apply the rule. Here's what the law says, what the 800 square foot figure means, who may qualify, and what a builder would look at on your lot before anyone sketches two units on it.

(An ADU is an additional home on the same lot as the main house; a junior ADU, or JADU, is a unit created within the space of the house itself. Our ADU overview covers the basics.)

What AB 956 changes

AB 956 (Chapter 791, Statutes of 2026) was approved by the Governor on September 29, 2026. It amends Government Code section 66323, the state's list of ADUs a city must approve ministerially, which today covers one detached, newly built ADU on a single-family lot. The new text reads:

"Two detached, new construction, accessory dwelling units that do not exceed four-foot side and rear yard setbacks for a lot with a proposed or existing single-family dwelling."

In plain English, once it takes effect:

• Two, not one. On a qualifying single-family lot, the state-required number of new detached ADUs goes from one to two.
• Four-foot setbacks. A city can't require side or rear setbacks larger than four feet for these units. That makes room; it doesn't make two units fit.
• A size cap the city may set: no more than 800 square feet of livable space per unit (more below).
• The JADU trade-off. If two detached ADUs are built this way, the city doesn't have to approve a junior ADU too, though it may.

The rule applies in every city and county, Los Angeles included, and overrides a conflicting local ordinance; building, health and safety codes and the California Coastal Act still apply. AB 956 also widens the HOA and deed-restriction protections for ADUs to lots "zoned to allow" single-family homes, not only lots "zoned for" them.

Concept illustration: before and after AB 956.

When it starts, and what Los Angeles hasn't said yet

AB 956 is not an urgency law, so it takes effect on January 1, 2027. Until then, the current one-detached-ADU rule stays in place.

As of October 30, 2026, three things are still open:

• Los Angeles hasn't published how it will apply AB 956. Its current ADU memo and City Planning's September 3, 2026 draft ADU ordinance both still describe one state-path detached ADU per single-family lot, and the draft isn't law yet.
• State guidance isn't out. HCD, the state housing department, hasn't published AB 956 guidance.
• Early applications. No official document we reviewed says whether an application filed before January 1, 2027 can use the new rule. Don't plan around early filing until the city or the state says so.

A simple picture of the lot

                         STREET
  +--------------------------------------------------+
  |  [ MAIN HOUSE ]  existing or proposed            |
  |    - one ADU inside the house or a detached      |
  |      garage, plus a JADU (Menu A) or the city's  |
  |      choice (Menu B)                             |
  |                                                  |
  |  [ ADU 1 ]                       [ ADU 2 ]       |
  |  detached, new build             detached,       |
  |                                  new build       |
  |                                  (what AB 956    |
  |                                   adds)          |
  +--------------------------------------------------+
   Side and rear setbacks: a city may not require more than 4 ft
   Size: a city may cap each detached unit at no more than
         800 sq ft of livable space

Concept illustration: a single-family property with two detached ADUs. Actual eligibility, placement and permitted size depend on the property and local requirements.

From January 1, 2027, the state-required options on one single-family lot come down to two menus. Menu A is what state law already covers today; Menu B is new.

The state-required path tops out at three ADU or JADU units plus the house, the most a city must approve, not a set you have to build. How HCD and Los Angeles will apply these combinations hasn't been published.

What "up to 800 square feet each" really means

The law says a city "may impose" on a detached, new-construction ADU "a total floor area limitation of not more than 800 square feet of livable space." That means:

1. It's a cap a city may set, not a size you're promised.
2. It's not a minimum.
3. It's livable space, the law's term for the area meant for living, sleeping, eating, cooking or sanitation.

The 800 square foot figure isn't new; what's new is that it can apply to each of two detached units.

Los Angeles today. LA's current memo, written before AB 956, caps the state-path detached ADU at 800 square feet and a detached ADU under LA's own ordinance at 1,200. LA hasn't published 2027 numbers, and how the two kinds combine on one lot after January 1, 2027 isn't settled.

Who may qualify for two detached ADUs

From the amended text, the rule applies when there's a building permit application, the lot sits in a residential or mixed-use zone with an existing or proposed single-family home, and both ADUs are detached and newly built.

The rule sets no minimum lot size, lot-coverage limit or owner-occupancy requirement. That doesn't mean any lot works: it still has to hold the house, two units, the setbacks, safe access and utility routes, and the plans still have to pass review. Not every property qualifies; the checklist below is where the answer comes from.

Concept illustration: a lot with a detached garage and open backyard.

What still needs checking on your property

• Jurisdiction and zone. Los Angeles, its neighboring cities and unincorporated LA County each adopt their own ADU ordinance and review their own permits, so implementation can differ, and the zone must be residential or mixed-use. Local details here are for the City of Los Angeles.
• Height. A city may cap height at the state's figures (16 feet, or 18 feet near major transit, plus two feet there for a roof pitch matching the house), as LA does today.
• Fire separation near property lines. LADBS's rule for converted units requires 1-hour fire-rated walls where an unsprinklered unit is under five feet from a property line; four feet is inside that, and plan check confirms how it applies to a new unit.
• Fire zone, hillside, coastal and historic districts. Each has its own rules: LA's memo says its hillside fire-zone ADU restriction may not be enforced on state-path units and allows a state-path detached ADU of up to 800 square feet in a historic overlay zone, and the Coastal Act still applies. Settle these early.
• Easements, sewer and utilities. A new detached ADU may need its own utility connection, and LA's clearances can include LADWP sign-off near a utility easement, sewer availability and LAFD access approval. Each unit needs its own address.
• Fees. Project-specific. State law limits ADU impact fees (SB 1117 changes the formula for ADUs over 750 square feet from January 1, 2027); in LA, school fees apply above 500 square feet and utility connection charges can apply. We don't quote amounts.
• HOA. Rules can't effectively prohibit or unreasonably restrict a qualifying ADU, but reasonable restrictions remain allowed (see the FAQ). Read your CC&Rs early.
• Existing structures. Raise anything unpermitted at the start; legalizing it is a separate LADBS process, and legalized units count toward the lot's limits.

Concept illustration: a footprint staked out near the property line.

Planning a second detached ADU in Los Angeles: a builder's view

These aren't AB 956 rules, just the questions a builder asks before design, whether the units are for family, long-term rental or both.

• Three buildings, not two. With the house, two units, four-foot setbacks and possibly fire-rated walls, where does each unit sit so yards, windows and privacy still work?
• Paths from the street. How does a tenant, a parent with a cane, or a firefighter reach the back unit? Fire access review can shape where it goes.
• Utility runs. A unit at the back of the lot means longer water, sewer and power runs; ask early about sewer availability.
• The existing garage. Convert it or remove it? LA's memo says state-path ADUs don't have to replace parking that's removed.
• Construction access. A narrow side yard, a slope or mature trees change how materials reach the back, as does living in the house during the work.
• Phasing. One unit now, one later? Plan the site for both from the start.

Costs aren't covered here; see our ADU cost breakdown for Los Angeles.

Concept illustration: a slab formed behind a house, reached through a narrow side yard.

Common misunderstandings

"This is the same 'two ADUs on one lot' I've already heard about." What state law already covers is one detached ADU plus a JADU (and a converted ADU): Menu A. AB 956's new piece is a second newly built, detached ADU. Our garage conversion vs. JADU guide covers the inside-the-house options.

"Ministerial means no plan check." It means no discretionary review or public hearing; plan check against building, fire and health codes still happens.

Frequently asked questions

Is AB 956 law yet, and when can I use it?

It was chaptered on September 29, 2026 and takes effect January 1, 2027. Los Angeles hasn't said how it will apply it, and nothing official we reviewed says an earlier application can use it.

Can I build two detached ADUs on my property?

Possibly, from January 1, 2027, if your lot meets the conditions above and the plans pass review. Not every property qualifies.

Is there a minimum lot size?

No. What decides it is whether the house, two units, setbacks, access and utilities fit and pass review.

Can my HOA stop me?

It can't ban or unreasonably restrict an ADU that meets state ADU law on a lot zoned for single-family use, and from January 1, 2027 that covers lots zoned to allow single-family use. Reasonable restrictions still apply, so read your CC&Rs early.

Can I use the units as short-term or vacation rentals?

No. Rentals must run longer than 30 days.

Can I sell an ADU separately from the house?

Generally no. State law allows it only in narrow cases, and LA's condo-sale option is still only a draft.

Official sources

• AB 956 bill text (Chapter 791, Statutes of 2026): https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520260AB956
• Governor's signing release, September 29, 2026: https://www.gov.ca.gov/2026/09/29/governor-newsom-signs-housing-legislation-cementing-californias-record-progress-to-reduce-unsheltered-homelessness-and-build-more-homes/
• Los Angeles Zoning Administrator Memo 143, Revision 1: https://planning.lacity.gov/odocument/be4db130-aa38-4637-b35a-d24304d50ff2/ZA_Memo_143_Revision_1_Chapter1.pdf
• LADBS ADU page: https://dbs.lacity.gov/adu
• LADBS Information Bulletin P/BC 2026-150 (ADU conversions): https://dbs.lacity.gov/sites/default/files/efs/forms/pc17/accessory-dwelling-unit-conversion-of-existing-detached-structure.pdf
• LA City Planning, Missing Middle LA hearing page (draft ADU ordinance): https://planning.lacity.gov/missing-middle-la-public-hearing

General information about a new law, current as of October 30, 2026. Not legal advice. What applies to a specific property depends on the jurisdiction, the lot and the plans.

Thinking about two units on your lot?

If you're wondering what your lot could hold, Hillstar Construction Inc. can look at your lot and plans with you, talk through what may fit, and walk you through what the city's permit process asks for. The city makes the final call when it reviews the plans. You can reach us at hillstarla.com or 310-975-7590. There's more on our Los Angeles ADU page and in our guide to choosing an ADU builder in Los Angeles.

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