California Housing Laws, Decoded: SB 9, SB 684, SB 1123, AB 956, AB 1751, SB 79

	AB 1033ADU condo sales	SB 9Duplex + lot split	SB 684 / SB 1123Starter Home Revitalization Act		NEW 2027AB 956Two detached ADUs	NEW 2027AB 1751Missing middle townhomes	SB 79Housing near transit
	AB 1033ADU condo sales	SB 9Duplex + lot split	Filed through Dec 31, 2026	NEW 2027Filed from Jan 1, 2027 (SB 1116 rewrite)	NEW 2027AB 956Two detached ADUs	NEW 2027AB 1751Missing middle townhomes	SB 79Housing near transit
In effect	Since Jan 1, 2024. Now Gov. Code 66342.	Since Jan 1, 2022. Gov. Code 65852.21 and 66411.7.	SB 684 since Jul 1, 2024. SB 1123 since Jul 1, 2025.	Applications received on or after Jan 1, 2027 (SB 1116, signed Sep 29, 2026).	Signed Sep 29, 2026. Effective Jan 1, 2027.	Signed Sep 29, 2026. Effective Jan 1, 2027.	Signed Oct 10, 2025. Applies in cities from Jul 1, 2026. Unincorporated areas wait for the 7th housing element cycle.
City opt-in required	YES. No city condo ordinance, no ADU condo sale. The state-only path covers homes built by qualified nonprofits and sold to income-qualified buyers.	No. Mandatory and ministerial. Charter cities included. 60 days to decide a complete application or it is deemed approved.	No. Mandatory and ministerial. 60 days to decide a complete application or it is deemed approved. Paused in Altadena ZIPs 91001 and 91003 for filings from Oct 1, 2026 (SB 1090).	No. Mandatory and ministerial. Same 60-day deemed-approved clock and same Altadena pause.	No. Ministerial approval.	No. Applies statewide except the City and County of San Francisco.	No. A city may adopt a local alternative plan that the state housing department reviews.
What it does	Lets the home and its ADU(s) be sold as separate condos where the city allows it. Creates no new building rights.	On one single-family lot in an urban area: build up to 2 units, split into 2 lots, or both.	Subdivide and build up to 10 homes on a multifamily lot up to 5 acres, or a vacant single-family lot up to 1.5 acres. Site must be substantially surrounded by urban uses.	Vacant single-family lot cap stays 1.5 acres. The 5-acre multifamily limit and the surrounded-by-urban-uses test give way to the state urban-site test. New screen: base zoning allows no more than 15 units (or 26,250 sf where zoning has no unit cap), unless the lot is a housing element lower-income site that delivers its affordable share.	On a lot with an existing or proposed single-family home, the city must approve 2 detached new ADUs (was 1). CC&Rs cannot ban or unreasonably restrict ADUs on lots zoned to allow single-family use.	Ministerial path to build and map ownership townhomes on multifamily-zoned lots, or on lots zoned only for single-family with no permanent home (unless abandoned and uninhabitable). Not on SB 79 sites.	Housing is an allowed use on residential, mixed-use or commercial zoned sites within 1/2 mile of a qualifying rail or bus rapid transit stop. The 1/4 to 1/2 mile ring applies only in cities of 35,000+.
Units per lot	Set by ADU law. Through 2026: home + 1 converted ADU + 1 junior ADU + 1 detached ADU. A junior ADU can never be sold separately.	2 units on one lot. With a split: 2 lots, each at least 40% of the original and 1,200 sf (a city may allow smaller), then the city need not allow more than 2 units per new lot, ADUs included. SB 9 alone guarantees 2 per lot, not 4.	Up to 10 parcels and up to 10 units. Both caps apply. Parcels at least 600 sf (multifamily) or 1,200 sf (single-family).	Same 10 parcel and 10 unit caps. Parcels may drop to 480 sf (multifamily) or 960 sf (single-family) if the average stays 600 or 1,200 sf.	2 detached ADUs plus the converted-ADU option. The city need not also allow a junior ADU when 2 detached ADUs are built.	Up to 150 units, at least 75% of the housing element default density. 11+ units: 10% lower income for 45 years, or the local inclusionary rate if higher.	City cannot cap density below 80 to 120 units/acre by tier and distance. Up to 160 next to the stop. Minimum 5 units and 30 units/acre.
Home size	Set by ADU law. Detached ADU up to 1,200 sf. Attached ADU up to 50% of the main home, but the city must still allow at least 800 sf.	No cap. City rules cannot block two units of at least 800 sf each.	Project average of 1,750 net habitable sf or less. Stairs counted.	Average stays 1,750 sf. Stairs and enclosed bike parking no longer counted.	City may cap each detached ADU at 800 sf of livable space on this path.	Project average of 1,750 net habitable sf or less.	Project average of 1,750 net habitable sf or less.
Height	ADU law: city limit cannot be below 16 ft detached (18 ft near major transit, plus 2 ft for roof pitch), or below 25 ft attached unless local zoning is lower.	Not set by SB 9. Local objective standards apply unless they block two 800 sf units.	Not set. On vacant single-family lots, no lower than existing zoning allows.	On vacant single-family lots, still no lower than existing zoning, and height limits cannot cap the number of floors.	City may apply the ADU limits of 16 to 18 ft for detached units (plus 2 ft for roof pitch near transit).	Townhome means 3 stories or fewer.	City cannot cap height below 55 to 75 ft by tier and distance. Up to 95 ft next to the stop.
Setbacks	ADU law: 4 ft max side and rear. None for conversions or same-footprint rebuilds.	4 ft max side and rear. None for existing structures or same-footprint rebuilds. No state cap on front setbacks.	4 ft side and rear from the original lot line. No setback between units beyond building code. No covered parking required. Minimum FAR 1.0 (3 to 7 units) or 1.25 (8 to 10).	4 ft side and rear still applies. Front setback max 10 ft. No interior setbacks between new parcels beyond building code. Minimum FAR 1.25 for every project.	4 ft side and rear.	Local objective standards, but they cannot block 75% of default density or require covered parking.	Local setbacks apply only if they do not prevent the required height, density and FAR.
Tenants + owner occupancy	Lender written consent, CC&Rs, HOA sign-off if one exists, utility notice and a safety inspection. No owner-occupancy rule for ADUs on single-family lots.	Lot split: owner signs an affidavit to live in one unit for 3 years. Rentals over 30 days. No demolishing or altering housing tenant-occupied in the last 3 years. Ellis Act sites (15 years) excluded.	No owner-occupancy rule. Cannot demolish or alter rent-restricted or rent-controlled housing, or housing tenant-occupied in the last 5 years. Local inclusionary rules apply.	Same protections. New Civil Code 714.9 voids CC&Rs that block these projects, except inside common interest developments.	Rentals over 30 days. No owner-occupancy rule for ADUs on single-family lots.	Ownership only: fee simple, condo, limited-equity co-op, land trust or TIC. Cannot demolish or alter rent-restricted or rent-controlled housing. Excludes lots that had 5+ units in the last 5 years.	No owner-occupancy rule. Over 10 units: 7% extremely low, 10% very low or 13% lower income. Limits on demolishing rent-controlled units occupied in the last 7 years.

Swipe the table sideways to see every law.

Informational only. Not legal advice. Verify with your city and a qualified professional before acting. SB 79 height, density and FAR numbers, and the AB 1751 75% density figure, are floors a city must allow, not caps. City-specific rules, overlay zones and utility capacity still decide what a lot can actually support.

Also changing for applications filed from January 1, 2027

AB 1621. Cities may require no more than 2 rounds of plan check on a housing building permit, then may deny if it still does not comply.
SB 1117. ADU impact fees apply only to the area above 750 sf, for up to 2 ADUs on a lot.
SB 1014. On request, the city must give a good-faith list of the improvements it may require, with costs for work it builds, within 30 business days.
AB 2601. SB 9 and SB 684/1123 building permits can be processed alongside the map.

Six claims we keep seeing that the statutes do not support

SB 9 gives you 4 units on one lot.

SB 9 itself guarantees 2 units per lot. Four homes under SB 9 alone takes the lot split, 2 on each new lot, and after a split the city need not allow more. Whether ADUs can add to an unsplit lot is a separate ADU law question.

SB 684 and SB 1123 allow 10 units or 10 parcels.

Both caps apply at once: no more than 10 parcels and no more than 10 units.

1,750 square feet is the maximum home size.

It is a project average, not a per-home cap. For SB 684 and SB 1123 applications filed from 2027, stairs and enclosed bike parking stop counting toward it.

AB 1033 gives you 3 units.

AB 1033 grants no units. It lets a city opt in to selling ADUs as condos. A junior ADU can never be sold separately.

SB 79 covers residential sites near high-quality transit.

It covers residential, mixed-use and commercial zoned sites near qualifying rail and bus rapid transit stops. Its density and height numbers are floors the city must allow, not caps.

SB 1116 sets 2 to 3 stories.

The statute sets no story count. On vacant single-family lots it says height limits apply to physical height only and cannot restrict the number of floors.

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Primary sources (California Legislative Information): AB 1033 (2023) · SB 9 (2021) · SB 684 (2023) · SB 1123 (2024) · SB 1116 (2026) · AB 956 (2026) · AB 1751 (2026) · SB 1090 (2026, controlling merged text) · SB 1426 (2026, current SB 9 text) · SB 79 (2025) · AB 1621 (2026) · SB 1117 (2026) · SB 1014 (2026) · AB 2601 (2026). Governor's signing release for the 2026 package, September 29, 2026, at gov.ca.gov.