Signed into Law - Effective January 2025

SB 1211

Up to 8 detached ADUs on a lot with an existing multifamily building, never more than the lot's existing unit count, with ministerial approval

Key Benefits

Massive ADU Expansion

Detached ADUs up to the lot's existing unit count (8 maximum), plus conversion ADUs inside the existing building

Ministerial Approval

Streamlined ministerial approval eliminates discretionary review

Zero Parking

Zero parking requirements save $25,000-$75,000 per space

Frequently Asked Questions

What is SB 1211 and how does it differ from existing ADU laws?

SB 1211 (Skinner, Chapter 296, Statutes of 2024) was signed on September 19, 2024 and took effect January 1, 2025. It amended Government Code §§ 66313, 66314 and 66323. Before SB 1211, a city had to approve no more than 2 detached ADUs on a lot with an existing or proposed multifamily building. SB 1211 raised that to up to 8 detached ADUs on a lot with an existing multifamily building, never more than the number of existing units on the lot (§ 66323(a)(4)(A)(ii)). A lot with a proposed multifamily building stays at 2 (§ 66323(a)(4)(A)(iii)). So a duplex still gets 2 detached ADUs, a triplex now gets 3, a fourplex 4, and a building with 8 or more units gets 8. SB 1211 also: (1) bars cities from imposing any objective development or design standard that § 66323 doesn't authorize on ADUs that qualify under that section (§ 66323(b)); (2) bars cities from requiring replacement of an uncovered parking space demolished or converted for an ADU, adding to the existing rule for garages, carports and covered parking (§ 66314(d)(11)); and (3) defines "livable space" (§ 66313(e)), which decides which non-living areas of a multifamily building can be converted into ADUs under § 66323(a)(3). SB 543 (Chapter 520, Statutes of 2025, effective January 1, 2026) later amended § 66323(a) to require approval of any combination of the units it lists.

How many ADUs can I build on my multifamily lot under SB 1211?

The lot must be in a residential or mixed-use zone and already have a multifamily building (§ 66323(a)). HCD treats a multifamily building as one structure with two or more attached units, such as a duplex, triplex or apartment building; several detached houses on one lot don't count (HCD ADU Handbook, March 2026, p. 8). On a qualifying lot you can build up to 8 detached ADUs, never more than the number of existing units on the lot (§ 66323(a)(4)(A)(ii)). If the multifamily building is only proposed, the limit is 2 (§ 66323(a)(4)(A)(iii)). HCD says detached ADUs already legalized on the lot may count toward that cap (HCD letter to the City of Los Angeles, March 24, 2026). The city must also allow conversion ADUs inside parts of the existing building not used as livable space, such as storage rooms, boiler rooms, passageways, attics, basements or garages within the building: at least 1, up to 25% of the existing units (§ 66323(a)(3)). The two types can be combined (§ 66323(a); HCD ADU Handbook, p. 17). Examples, where the building has space to convert: a duplex gets 2 detached plus 1 conversion ADU, an 8-unit building 8 plus 2, and a 40-unit building 8 plus 10.

What size, height and setback limits apply to SB 1211 ADUs?

The ADUs must be detached from the multifamily building, though they may be attached to each other (HCD ADU Handbook, March 2026, p. 41). The city can apply only the height limits in § 66321(b)(4)(A)-(C) and side and rear setbacks of no more than 4 feet (§ 66323(a)(4)(A)(i)). The height limit is 16 feet; 18 feet within a half-mile walk of a major transit stop or high-quality transit corridor, plus 2 feet to match the roof pitch of the main building; or 18 feet on a lot with a multistory multifamily building. The city can't require changes to an existing building whose side or rear setbacks are under 4 feet (§ 66323(a)(4)(B)). Because § 66323(b) bars standards the section doesn't authorize, state law sets no floor-area cap on these ADUs, and the city can't apply other standards such as front setbacks, lot coverage, floor area ratio or open space (HCD ADU Handbook, pp. 16, 19 and 37). The 800-square-foot cap in § 66323(a)(2) applies only to a detached ADU on a single-family lot.

Can I combine SB 1211 with SB 9 lot splits?

Generally no. An SB 9 lot split (Gov. Code § 66411.7) is only available for a parcel in a single-family residential zone, and the split can't require demolishing or altering rent-controlled housing or housing occupied by a tenant in the last three years. After a split, the city never has to allow more than two units on either new parcel, ADUs and junior ADUs included (§ 66411.7(j); HCD ADU Handbook, March 2026, p. 37). SB 1211's allowance of up to 8 detached ADUs (§ 66323(a)(4)(A)(ii)) applies only to a lot with an existing multifamily building, capped at its existing unit count. It doesn't work in the other order either: if ADUs bring a lot above four total units, the city doesn't have to approve an SB 9 split (HCD ADU Handbook, p. 37). So the two laws rarely apply to the same lot.

What are the parking requirements for SB 1211 ADUs?

None. A city can't impose parking requirements on ADUs that qualify under § 66323, because § 66323(b) bars any standard that section doesn't authorize (HCD ADU Handbook, March 2026, pp. 19 and 33). SB 1211 also bars a city from requiring you to replace an uncovered parking space that is demolished or converted for an ADU (§ 66314(d)(11)). This is a significant cost savings, as eliminating parking can reduce construction costs by $25,000-$75,000 per space and maximize developable land area.

Sources

Last reviewed October 12, 2026.

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