ADU rules in Los Angeles
Every rule the property report applies, with its source and whether we have confirmed it. State law sets the floor; the city may be more generous, not stricter. Where a city rule is still being checked, the report says "Check with LADBS".
This is the rules engine's source of truth. Every rule the report applies must trace to a line here, and every line here carries its source and a status:
- Confirmed: settled state law, or read in an HCD document or a county memo during this project. Section numbers follow the 2024 renumbering (Gov. Code §§ 66310–66342); check the exact subsection against the current code when you encode each rule, and store the citation with the rule.
- Verify: correct as far as we know, but check the current text before launch. Note the date you checked it.
Before launch, have a land-use attorney or permit expediter read this file once. It's the part of the product that has to be right.
State law sets the floor. A city may be more generous, not stricter (Gov. Code §§ 66314–66342, the ADU chapter, renumbered in 2024). If the rules in a city's ordinance conflict with state law, state law wins. HCD reviews ordinances and publishes findings letters.
1. Which rules apply: jurisdiction first
The report must work out who regulates the property before it says anything else.
| Property is in | Who regulates | Plan programs |
|---|---|---|
| City of Los Angeles | LADBS (building) and LA City Planning (zoning) | LADBS Standard Plan Program |
| Unincorporated LA County (Altadena, East LA, etc.) | LA County Planning (DRP) and Public Works | LA County pre-approved plans |
| Another city in the county (Pasadena, Glendale, Santa Monica, Long Beach…) | That city | That city's own program, if any |
For other cities, show the state-law baseline and say clearly that local rules can be more generous and the city decides. Don't claim city-specific rules for cities we haven't encoded.
2. Kinds of ADU
| Kind | What it is | Size | Source / status |
|---|---|---|---|
| Detached ADU | New separate building | Up to 1,200 sq ft. A city must always allow at least 800 sq ft at 16 ft tall with 4 ft side and rear setbacks. | Gov. Code §§ 66314, 66321. Confirmed |
| Attached ADU | Addition attached to the home | Up to 50% of the existing home's floor area or 1,200 sq ft, whichever is less. 800 sq ft is always allowed. | § 66321. Confirmed |
| Conversion | Turn existing space (garage, part of the home, accessory building) into an ADU | Existing space, plus up to 150 sq ft added for entry. | § 66323. Confirmed |
| Junior ADU (JADU) | Inside the existing single-family home, including an attached garage | Up to 500 sq ft. Efficiency kitchen required. Its own bathroom or a shared one. | §§ 66333–66339. Confirmed |
How size is measured (SB 543, from January 1, 2026): every square-foot limit means interior livable space: space for living, sleeping, eating, cooking or sanitation. Wall thickness, garages and decks don't count. Confirmed (LA County DRP memo on SB 543 / AB 1154, December 2025).
Combining (SB 543, from January 1, 2026): on a single-family property you can build a conversion ADU, a JADU and a detached ADU together under the ministerial path (§ 66323). On a multifamily property, converted and detached ADUs can be combined. Confirmed.
3. Height and setbacks (detached ADU)
| Rule | Value | Source / status |
|---|---|---|
| Height, standard | 16 ft | § 66321(b)(4). Confirmed |
| Height near transit | 18 ft within half a mile walking of a major transit stop or a high-quality transit corridor, plus 2 ft more to match the main home's roof pitch (so up to 20 ft) | § 66321(b)(4). Confirmed |
| Height, on a multifamily property with a multistory building | 18 ft | § 66321(b)(4). Confirmed |
| Height, attached ADU | 25 ft or the zone's height limit, whichever is lower (no more than two stories) | § 66321(b)(4). Confirmed |
| Side and rear setbacks | 4 ft maximum the city can require | § 66314(d)(7). Confirmed |
| Front setback | May not be applied to block an 800 sq ft ADU | § 66321. Confirmed |
| Conversions | No setback for an existing structure converted in place, or rebuilt in the same footprint | § 66314(d)(7). Confirmed |
The report's "Height here" must check the transit distance. Use the state's High Quality Transit Areas / major transit stops data (Caltrans, SCAG).
4. Parking
No parking may be required for the ADU if any of these apply (§ 66322). Confirmed.
- Within half a mile walking of public transit.
- In an architecturally and historically significant historic district.
- Part of the existing home or an existing accessory building.
- On-street parking permits are required but not offered to the ADU occupant.
- A car share vehicle is within one block.
Replacement parking: when a garage, carport or covered parking is demolished or converted for an ADU, the city can't require it to be replaced (§ 66314(d)(11)). Confirmed.
Most of the City of Los Angeles is within half a mile of transit; compute it, don't assume.
5. Owner occupancy and rentals
| Rule | Value | Source / status |
|---|---|---|
| ADU owner occupancy | Not allowed to be required. Permanent since AB 976 (2023) | § 66315. Confirmed |
| JADU owner occupancy | Required only if the JADU shares a bathroom with the main home. With its own bathroom, no owner-occupancy rule, and covenants can't include one. | AB 1154, from January 1, 2026. Confirmed |
| Short-term rentals | ADUs and JADUs rent for more than 30 days. AB 1154 applies this to all JADUs and § 66323 ADUs; the city may apply it to others | AB 1154. Confirmed |
| Selling an ADU separately | Only if the city has opted in under AB 1033 (2023) or the ADU is built by a qualifying nonprofit. Don't tell users they can sell an ADU separately in LA City unless the city has adopted AB 1033. | § 66341. Verify LA City's status |
6. Fees
| Fee | Rule | Source / status |
|---|---|---|
| Development impact fees | None on an ADU of 750 sq ft or less, or a JADU of 500 sq ft or less (interior livable space). Above that, charged in proportion to the main home's size. | SB 543, from January 1, 2026; § 66324. Confirmed |
| School fees | None on an ADU or JADU of 500 sq ft or less. | SB 543. Confirmed |
| LAUSD school fee above 500 sq ft | $5.17 per sq ft (residential rate adopted June 2024). LAUSD adjusts it every two years. | Verify the current rate |
| Utility connection fees | No new connection or capacity charge for a conversion ADU or JADU unless built with a new single-family home. | § 66324. Confirmed |
| Plan check and permit | LADBS fee schedule, based on valuation. Lower with a standard plan. | Verify the current schedule |
| LA City park fee (Quimby) | Not charged on ADUs under 750 sq ft (impact-fee exemption). Check LA's treatment above 750 sq ft. | Verify |
7. Review time and appeals
| Step | Time | Source / status |
|---|---|---|
| Completeness | The city has 15 business days from submittal to say in writing whether the application is complete, and list what's missing and how to fix it. Same 15 days for each resubmittal. LA County: if no notice in 15 business days, the application is deemed complete. | SB 543, from January 1, 2026. Confirmed |
| Decision | 60 days from a complete application to approve or deny. If the city misses it, the application is deemed approved. | § 66317. Confirmed |
| Appeal | Written appeal of an incompleteness finding or denial; final written decision within 60 business days. LA County: appeal to the Regional Planning Commission within 14 calendar days. | SB 543. Confirmed (County); verify LA City's process |
| Coastal zone | With a certified local coastal program, the coastal development permit decision is due within 60 days, and appeals to the Coastal Commission are removed. Without one, the Commission reviews on a 60-day clock. | AB 462, effective October 10, 2025 (urgency). Confirmed |
8. After a disaster (Palisades and Eaton fires)
AB 462 (effective October 10, 2025): a detached ADU can get its certificate of occupancy before the main home is rebuilt if the county had a state of emergency declared on or after February 1, 2025, the main home was substantially damaged or destroyed in that event, and the ADU has permits and passed its inspections. Confirmed. This applies to the Palisades (LA City) and Eaton (Altadena, unincorporated county) fire areas. Show it in reports for parcels in those burn areas.
Also check the City's and County's fire rebuild rules (executive orders, rebuild ordinances) before launch. Verify.
9. Where LA City is stricter or different (check each)
These are the city-level rules the report most often gets wrong. Encode each only after reading the current LA City ADU ordinance (LAMC § 12.22 A.32/A.33 and the 2025–2026 amendments) and the HCD findings letters for Los Angeles.
- Very High Fire Hazard Severity Zones and hillsides. LA City limits detached ADUs in hillside areas and VHFHSZ, especially on streets narrower than the city's standard (fire access). Fire sprinklers are required in VHFHSZ. Verify the exact rule and whether HCD has accepted it. CAL FIRE's 2025 FHSZ maps added areas: use the current map.
- Fire department access (LAFD). Every part of the ADU's exterior must be within 150 ft of a fire hydrant along an access path, or the ADU needs sprinklers or other measures. Many deep LA properties fail this. Verify LAFD's current requirement and show it as "May need fire sprinklers", never as "Doesn't fit".
- Historic areas (HPOZ). ADUs are allowed; design review may apply to what's visible from the street. Verify the current HPOZ treatment.
- Specific plans, overlays and the Coastal Zone. Venice, Pacific Palisades, San Pedro, Playa del Rey and others. Note them; don't block.
- Easements, sewer lines and power lines. Out of scope for an automated report. Say a survey confirms.
When a city rule is unverified, the report says "Check with LADBS" rather than "Fits" or "Doesn't fit".
10. More than one home (routes to Vivienda)
| Path | What it allows | Source / status |
|---|---|---|
| SB 9 lot split (single-family zones) | Split one property into two; up to two homes on each (four total, counting ADUs differently by city). Owner must sign an affidavit to live in one of the homes for 3 years (lot split). Not in VHFHSZ (with exceptions), historic districts, and some other areas. | § 65852.21, § 66411.7. Confirmed; verify LA's SB 9 ordinance limits |
| SB 684 small lot subdivision (multifamily zones) | Up to 10 homes on a lot of 5 acres or less, approved ministerially, 60-day decision. | SB 684 (2023). Confirmed |
| SB 1123 (vacant single-family lots) | Extends SB 684 to vacant lots zoned single-family, from July 1, 2025. | SB 1123 (2024). Verify scope |
| SB 1211 (existing multifamily) | Up to 8 detached ADUs on a property with an existing multifamily building, not more than the number of existing homes; plus conversions of non-living space (at least 1, up to 25% of the existing homes). | SB 1211, from January 1, 2025. Confirmed |
| LA City small lot subdivision (RD, R3 and similar) | City's own small lot ordinance, the path Vivienda uses for four homes on a 50 × 150 property. | Verify current ordinance |
The report shows "Room for more than one home: may qualify" and a "Talk to Vivienda" button. It never says a property qualifies; that takes a review.
11. Unpermitted ADUs
AB 2533 (2024, from January 1, 2025): an ADU built without permits before January 1, 2020 can be legalized. The city can require only health and safety fixes, and may waive fees. Confirmed. Add a "Have an unpermitted ADU?" guide and a report line when assessor data shows more homes than permits.
12. Plan programs
- LA City, LADBS Standard Plan Program. Pre-approved plans from private firms, numbered ADU1 and up, plus SFH and MISC plans. With a standard plan, LADBS reviews the site-specific items (placement, foundation for the soil, utilities, fire access). The listing is paginated at
dbs.lacity.gov/standard-plans-page-filtered?page=N, with filters for Plan Type (ADU, MISC, SFH), Stories (1, 2, 3+) and Sq Ft bands (0–500, 501–800, 801–1200, 1201–1500, 1501–3000, 3000+). A partial seed is indata/plans-seed.json. Scrape every page; don't trust the seed's count. - LA County pre-approved ADU plans. Run by LA County (DRP / Public Works), including fire-rebuild plans for Altadena. Verify the current page and list.
- HCD-approved plans. Some plans (for example Cover ADU79) note state approval. Store it as a tag.
- Each plan page on ADUCheck credits the firm by name and links to the official listing. ADUCheck is never presented as the author.
13. Things the report must never say
- That a permit is guaranteed, or that the report is a permit.
- A property value increase.
- That an ADU can be sold separately (unless the city has opted in, see 5).
- Exact fees or costs as quotes. Say "about", give the source and date.
- That a property qualifies for more homes. Say "may qualify".
14. To verify before launch (added November 6, 2026)
Each of these is Verify until read in the current text and dated here. The report shows "Check with LADBS" until then.
| Item | Why it matters | Status |
|---|---|---|
| Zone 0 effective dates and phases (Board of Forestry rules approved August 2026) | The fire check's phase-in wording (no dates shown until verified) | Verify |
| Seller fire-zone disclosure requirements | The listing kit's fire summary and the "Selling" line on the fire check | Verify |
| Brush clearance distances by fire department (LAFD for the city; county fire for unincorporated areas) | The fire facts' "Required, 200 ft" line | Verify |
| 120 sq ft accessory building exemption, per city. LA City text read Nov 9, 2026 (secondary copy; amlegal blocked): sheds, playhouses and similar uses, one story, not more than 120 sq ft; not in Fire District No. 1; not with any heating, plumbing or electrical installation. So a powered office or pod is not exempt, and the current "electrical and plumbing do" wording overstates it. | The "Backyard office or pod" row and /plans/pods | Verify |
| State ADU code section numbers after the 2024 renumbering (Gov. Code §§ 66310–66342) | Every state-rule citation | Verify |
| Civil Code § 4751 (HOAs may set reasonable rules but cannot ban ADUs) | City pages, "Homeowner associations" | Verify |
15. Rules for the main house (R1, added November 9, 2026)
Shown on the live report only, under "Rules for the main house"; not in the PDF. They apply to the house, not to an ADU. They cover the base R1 zone in height district 1, off hillside and coastal areas, with no variation suffix (R1V, R1F, R1R, R1H) and no HCR district. Anything else returns "Check with LADBS".
Text read November 9, 2026 from the gocodebook.com copy of LAMC Chapter 1, which carries the ordinance history notes. codelibrary.amlegal.com was blocked by a bot check; re-check these against it before launch. Status: confirmed by the LAMC text (secondary host).
| Rule | Value | Citation |
|---|---|---|
| Front yard | 20% of the lot's depth, no more than 20 ft. Where developed lots with front yards within 10 ft of each other make up 40% or more of the frontage, the average of those (up to 40 ft): ask LADBS. | LAMC 12.08 C.1 |
| Side yards | 5 ft. On a lot under 50 ft wide, 10% of the width, at least 3 ft. New construction off hillside and coastal areas adds 1 ft for each 10 ft (or part) of height above 18 ft. A side wall over 14 ft tall and 45 ft long needs a 5 ft deep, 10 ft long offset. | LAMC 12.08 C.2(a), (b) |
| Rear yard | 15 ft. | LAMC 12.08 C.3 |
| Height | 33 ft; 28 ft when the top story's roof slope is under 25%. A 45° encroachment plane starts 20 ft up at the front and side setback lines. | LAMC 12.21.1 A; 12.08 C.5(a); 12.03 "Encroachment Plane" |
| Floor area (RFA) | 45% of the lot area (0.45) for all buildings on the lot. Required covered parking in the rear half is exempt up to 400 sq ft (200 sq ft otherwise). | LAMC 12.08 C.5(a); 12.03 "Floor Area, Residential" |
| Parking for the home | 2 spaces in a private garage. None can be required within half a mile of a major transit stop (AB 2097; City Planning memo, Dec 29 2022). | LAMC 12.21 A.4(a); Gov. Code § 65863.2 |
An ADU counts toward the lot's floor area, but no floor area limit can stop an 800 sq ft ADU, 16 ft tall, with 4 ft side and rear setbacks (LAMC 12.22 A.33(c)(1)(iii); Gov. Code § 66321(b)(3)).
The PDF's "Floor area used" is the existing home's floor area divided by the lot area (Assessor building area ÷ lot area), not a ZIMAS figure.
Sources read for this guide
- BB&K, "Governor Newsom Signs Four New Accessory Dwelling Unit Bills" (November 2025): AB 462, AB 1154, SB 9 (2025), SB 543.
- LA County Department of Regional Planning, memo on SB 543 and AB 1154 (December 2025).
- HCD ADU Handbook and the April 2026 fact sheet (earlier in this project).
- LADBS Standard Plan Program listing pages (October 2026).
- California Government Code §§ 66314–66342.