Two detached ADUs on one lot: what changes in 2027 (AB 956)
Until now, a Los Angeles homeowner could build one new detached ADU in the backyard, plus a conversion and a junior ADU. A new state law changes that ceiling. AB 956, signed by the Governor on September 29, 2026 (Chapter 791, Statutes of 2026), takes effect on January 1, 2027.
What AB 956 changes
It raises the number of new detached ADUs that a city must approve ministerially, without a hearing, on a lot with an existing or proposed single-family home: from one to two. For owners with a deep or wide lot, that means two independent cottages behind the main house.
| Detached ADUs approved by right | Up to two on a single-family lot, instead of one. |
| Junior ADU | If you build two detached ADUs this way, the city no longer has to approve a JADU on the same lot. |
| HOAs | The ban on HOA and CC&R rules that block state-compliant ADUs now also covers lots zoned to allow single-family homes. |
| Effective date | January 1, 2027. |
The catch: plan without a guaranteed JADU
Two detached units and a junior ADU are not automatically compatible. If a JADU matters to you, for example to keep a parent inside the main house, we compare both scenarios on your lot before you choose.
Impact fees: only the space above 750 sq ft
A companion bill, SB 1117 (Chapter 809), also from January 1, 2027, applies impact fees only to the square footage above 750 sq ft, for up to two ADUs on a lot. An 800 sq ft unit pays on 50 sq ft instead of 800.
File now or wait?
- One ADU planned: no reason to wait; current rules already allow it.
- Two detached ADUs planned: design now, and submit under the new rules from January 2027.
- Not sure: a feasibility check shows what your lot can hold under both sets of rules.
Two units also change the budget, the utilities and the financing. On a free call, we review your lot and tell you whether two detached ADUs fit, and in what order to build them.
Information summary as of November 2026, not legal advice. The chaptered text of AB 956 and SB 1117 is on leginfo.legislature.ca.gov; local details are confirmed for each address.
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