Section 01 | California ADU Laws
Section 01
California ADU Law - Complete Reference
California has enacted meaningful ADU legislation every year since 2017. This is not incremental tweaking — it is a systematic dismantling of the barriers that prevented density on existing lots. If you're a homeowner, these laws define exactly how many units you can add and what they'll cost to permit. If you're a developer or investor, they define your entitlement risk, your timeline, and your exit options. Here is every law that affects your Los Angeles project.
Every bill that affects what you can build, how fast, and what it costs.
The Full Legislative Timeline (2017-2026)
Bill | Effective | What It Does | Owner Benefits |
|---|---|---|---|
SB 1069 / AB 2299 / AB 494 | January 1, 2017 | Overrode all local ADU bans statewide. Required ministerial (non-discretionary) approval for ADUs. Legalized ADU construction in every California city regardless of local zoning ordinances. | ADUs are now a legal right in every LA neighborhood. No city can block them entirely. |
SB 13 / AB 68 | January 1, 2020 | Capped permitting at 60 days for complete applications. Reduced or eliminated impact fees for ADUs under 750 sq ft. Prohibited HOAs from unreasonably restricting ADU construction. Eliminated minimum lot size requirements. | No impact fees for smaller units. HOAs cannot block you. 60-day permit clock established. |
AB 881 / AB 3182 | January 1, 2021 | Suspended owner-occupancy requirements for ADUs through 2025 (later made permanent by AB 976). Required HOAs to allow ADUs and JADUs. Expanded multi-family ADU rights. | Investors and non-resident owners can build and rent ADUs freely. HOA override strengthened. |
SB 9 — HOME Act | January 1, 2022 | Ministerial approval for duplexes and urban lot splits on SFR-zoned lots. Combined with ADU law: up to 4 units on an intact lot. With lot split: up to 4 units per new lot (8 total on original parcel). Owner must occupy one lot for 3 years post-split. | SFR owners can double or quadruple unit count through lot splits and duplexes with no Planning Commission and no neighbor hearings. |
SB 10 | January 1, 2022 | Allows cities to voluntarily upzone parcels near transit or job centers to allow up to 10 units. Optional for cities — not a by-right entitlement. Separate from ADU law. | Relevant for Silver Lake, West Adams, and Hollywood corridors where cities may activate SB 10 upzoning. |
SB 897 / AB 2221 | January 1, 2023 | Codified 60-day approval mandate statewide. Height up to 18 ft (vs. standard 16 ft) within half mile of major transit. Allows ADU construction on lots with unpermitted work unless health/safety hazard. Removed fire sprinkler requirements in most ADU cases. | Transit-adjacent ADUs can be taller. No more permit blockage due to other unpermitted work on the property. Fire sprinkler cost savings. |
AB 916 | January 1, 2023 | Allows homeowners to convert interior space to a bedroom without a public hearing. Originally drafted with ADUs in mind — maximizes bedroom yield in garage conversions and JADUs. | More bedrooms per ADU without discretionary review. Directly boosts rental income potential per unit. |
AB 1332 | January 1, 2024 | Every city must publish a pre-approved ADU plan program online. Applications using a pre-approved plan receive a 30-day review (vs. 60 days for custom). HCD-approved modular plans accepted into all local programs. | Pre-approved plan path cuts review time in half. LADBS pre-approved plans available online — significant timeline reduction for budget-conscious clients. |
AB 1033 | January 1, 2024 | Allows ADUs to be sold as independent condominiums with separate title and financing in participating jurisdictions. San Jose adopted July 2024. San Diego adopted August 2025. More cities expected in 2026. | ADU becomes a full real estate asset — sellable as a condo. Exit strategy beyond rental-only hold. Transforms ADU ROI calculation for developers. |
AB 2533 | January 1, 2025 | Unpermitted ADU/JADU amnesty for units built before January 1, 2020. Cities must legalize if unit meets health and safety standards. No impact fees if no new utility connection required. City must provide written remediation checklist. | Thousands of LA homeowners can legalize pre-existing unpermitted units at low cost. Resolves liability exposure and enables legal rental income. |
AB 976 | January 1, 2025 | Permanently removes owner-occupancy requirement for standard ADUs. No sunset clause. You can rent your primary home and your ADU simultaneously. Full investment flexibility for non-resident owners. | Permanent investment-grade ADU freedom. No occupancy restriction on SFR ADU portfolios anywhere in California. |
SB 1211 | January 1, 2025 | Raises cap on detached ADUs on multifamily lots from 2 to up to 8, based on existing unit count. Allows conversion of parking and storage to ADUs (up to 25% of existing units). Eliminates replacement parking for garage conversions. Clarifies habitable space definition. | Multi-family investors can stack up to 8 new ADUs on a qualifying lot without full apartment entitlement. No replacement parking required. |
AB 462 | October 15, 2025 | Coastal ADU permits now subject to mandatory 60-day decision deadline. Coastal Commission appeals eliminated for standard ADUs. LA County fire zone exception: detached ADU can receive Certificate of Occupancy before primary dwelling is rebuilt. CDP runs concurrently with planning review. | Coastal ADUs no longer subject to indefinite review delays. Fire-affected Palisades and Altadena homeowners can legally occupy a new ADU while primary home reconstruction continues. |
AB 1154 | January 1, 2026 | Owner-occupancy requirement for JADUs narrowed: if a JADU has its own bathroom, owner-occupancy cannot be required. Only JADUs sharing sanitation with the main dwelling retain the requirement. All JADUs must be rented for 30+ days minimum. | JADUs with private bathrooms are now fully investor-friendly. Significantly expands JADU utility for rental portfolios on investor-owned properties. |
SB 543 | January 1, 2026 | 15-business-day completeness review deadline for ADU applications. Auto-deemed complete if city misses deadline. Codifies: 1 detached + 1 converted + 1 JADU per SFR lot. School fees waived for units under 500 sq ft. Fee protections extended to JADUs. All sizes measured in interior livable space only. | Cities can no longer stall applications indefinitely. Clear unit-per-lot rules. Fee savings on smaller units. Strongest permitting protection in California ADU history. |
SB 9 (2025 version) | January 1, 2026 | Requires local ADU ordinances to be submitted to HCD within 60 days of adoption. Non-submitted or non-compliant ordinances are automatically void — state default rules apply in their place. | Cities that ignore state ADU law lose their local ordinance. State default rules are the most permissive baseline and benefit project applicants directly. |
AB 1061 | January 1, 2026 | Extends SB 9 lot split and duplex rights to historic districts, provided no existing historic structure is demolished or altered. Previously HPOZ properties were ineligible for SB 9. | HPOZ neighborhoods in LA — Hancock Park, Carthay Circle, Bungalow Heaven, Windsor Square, Angelino Heights — are now eligible for SB 9 lot splits and duplexes for the first time. |
SB 1077 | July 1, 2026 | Coastal Commission and HCD must publish joint guidance to simplify and standardize ADU review in the Coastal Zone by July 2026. Public workshop required before publication. | Coming improvement for coastal ADU clients. Expected to create uniform permitting expectations across all LA Coastal Zone cities. |
How many units can I legally build?
The SB 543 Clarification (2026)
Single-family lot (standard):
1 detached ADU + 1 converted ADU (garage or interior) + 1 JADU =
3 additional units on one SFR parcel
Single-family lot (with SB 9 duplex, no split):
2 primary units + 2 ADUs =
4 total units on one SFR parcel
Single-family lot (with SB 9 lot split):
2 new lots, each with up to 2 units =
up to 4 units per lot, 8 total on original parcel
Multi-family lot (SB 1211):
Up to 8 new detached ADUs + converted ADUs (up to 25% of existing units) =
potentially 10+ units added to qualifying multi-family parcel
These are your legal rights under state law. If your city's local ordinance is non-compliant or not submitted to HCD, state default rules — which are more permissive — apply automatically.
Key ADU Development Standards
Standard | State Rule | LA-Specific Context |
|---|---|---|
Max ADU size | 800 sq ft interior livable space (detached); 500 sq ft (JADU) | SB 543 clarifies 'interior livable space' — exterior walls and stairs excluded from calculation |
Height — standard | 16 ft max for most detached ADUs | Applies across most LA residential zones; verify per project with LADBS or Pasadena B&S |
Height — transit adjacent | 18 ft max within ½ mile of major transit | Relevant for Hollywood corridors, Silver Lake, West Adams, portions of Brentwood and Bel Air |
Setbacks | 4 ft rear and side for new construction; 0 ft for conversions within existing footprint | HPOZ design review may add architectural constraints but cannot override state setback minimums |
Parking | No replacement parking for garage conversions, transit-adjacent ADUs, or historic district ADUs | SB 1211 eliminates replacement parking for multi-family garage conversions. Half-mile transit rule broadly applicable across LA |
Impact Fees | Zero for ADUs ≤750 sq ft; proportional for larger units (SB 13) | School fees also waived for ADUs and JADUs ≤500 sq ft interior livable space (SB 543) |
Permit timeline | 60-day approval once complete application received; 15-day completeness determination (SB 543) | If city misses 15-day completeness deadline, application automatically deemed complete — strong anti-stalling protection |
Pre-approved plans | 30-day review (vs. 60 days) when using city-published pre-approved ADU plans (AB 1332) | LADBS publishes pre-approved standard plans; using them cuts review time by up to 50% |
Owner-occupancy | Not required for standard ADUs (AB 976, permanent). JADUs with independent bathroom also exempt (AB 1154) | No occupancy requirement on investor-owned SFR ADUs in California as of Jan 1, 2025 |
Coastal Zone | 60-day CDP decision required; runs concurrently with planning review (AB 462) | Coastal Commission appeals eliminated for standard ADUs. LA Coastal Zone properties: Manhattan Beach, Hermosa Beach, Playa del Rey, Pacific Palisades |
Fire zone CofO | ADU can receive CofO before primary dwelling in LA County fire-emergency zones (AB 462) | Direct benefit for Palisades (90272) and Altadena (91001) rebuild clients — ADU habitable while main home is under reconstruction |
HOA restrictions | HOAs cannot unreasonably restrict ADUs or JADUs (AB 3182, SB 13) | HOAs may impose reasonable design standards but cannot effectively prohibit ADU construction |
Unpermitted amnesty | Units built before Jan 1, 2020 eligible for legalization if health/safety compliant (AB 2533) | LA estimated to have tens of thousands of qualifying pre-2020 unpermitted units — significant legalization opportunity |
The Permitting Timeclock is on Your Side
Before SB 543 (effective January 1, 2026), cities could stall ADU applications indefinitely by sitting on 'completeness' determinations for weeks or months. That era is over. Cities now have 15 business days to declare an application complete — and if they miss it, the application is automatically deemed complete under state law. Combined with the 60-day approval deadline, a fully prepared submittal from a licensed architect can achieve permit issuance in under 90 days in most LA jurisdictions. The bottleneck that used to be 6–12 months is largely gone for clients who submit correctly.