What's Required in Los Angeles
- ADU applications are ministerial: completeness notice within 15 business days, approval or denial within 60 days of a complete application (Gov. Code 66317)
- Combined building-mechanical permit covers building, electrical, plumbing and HVAC for a detached ADU on a one- or two-family lot; service connections need separate trade permits
- Permit fee is valuation-based with plan check at 90% of the permit fee: about $2,696 total at $150,000, $3,723 at $250,000
- LAUSD school fees for ADUs over 500 sq ft; city impact fees only for ADUs of 750 sq ft or more; exempt from park fees and the linkage fee
- At least 800 sq ft with 4-ft side and rear setbacks must be allowed; detached ADUs up to 1,200 sq ft, attached up to 50% of the house
- Height of at least 16 ft, or 18 ft within half a mile of a major transit stop, plus 2 ft for a matching roof pitch
- No parking required within half a mile of transit, in a historic district or for conversions; replaced garage parking not required
- Fire sprinklers not required unless required for the main house; new detached ADUs must have solar panels
- Owner-builders sign the declaration; contractors need a CSLB B license
Do You Need a Permit for an ADU in Los Angeles?
Yes, but not a discretionary one. Under California Government Code 66317 an ADU application is approved ministerially, without a hearing: the city must tell you within 15 business days whether the application is complete and must approve or deny it within 60 days of a complete application when a house already exists on the lot, or the application is deemed approved. The Department of Building and Safety (LADBS) issues the permit; the Department of City Planning clears zoning under the city's ADU ordinance (LAMC 12.22 A.33, Ordinance 186,481), and LADBS bulletin P/BC 2026-150 sets the building standards. A detached ADU on a one- or two-family lot gets a single combined building-mechanical permit covering building, electrical, plumbing and HVAC, with separate permits only for utility service connections. Converting a garage, using an LADBS pre-approved Standard Plan, or legalizing an unpermitted unit built before 2020 under AB 2533 are all ADU permits with their own paths.
Los Angeles ADU Rules by Scenario
| What you are doing | City filing | Rule |
|---|---|---|
| New detached ADU up to 800 sq ft, 4-ft side and rear setbacks | Combined building-mechanical permit, ministerial | Gov. Code 66323(a)(2); 60-day decision |
| Detached ADU up to 1,200 sq ft or attached up to 50% of the house | Combined permit; must meet local objective standards | Gov. Code 66314(d)(4)-(5); LAMC 12.22 A.33 |
| Garage or accessory-structure conversion (up to 150 sq ft expansion) | Building permit; no new setback required | Gov. Code 66323(a)(1); IB P/BC 2026-150 |
| Junior ADU within the house (with the ADU) | Building permit plus recorded JADU covenant | Gov. Code 66323(a)(1); LADBS JADU covenant form |
| ADU from an LADBS pre-approved Standard Plan | Site-specific plan check only | LADBS Standard Plan Program |
| Unpermitted ADU built before Jan. 1, 2020 | AB 2533 amnesty permit, no impact fees | IB P/BC 2026-161; substandard checklist instead of current code |
| Movable tiny house as an ADU | Ministerial approval; 4-ft setbacks, one per lot | IB P/ZC 2023-021 |
How Much Does an ADU Permit Cost in Los Angeles?
LADBS prices the combined permit on the valuation of the work and charges plan check at 90 percent of the permit fee, with surcharges on both. The city's Permit Fee Calculator, run as a new one- or two-family building, returns a permit total of $1,444.44 and plan check of $1,252.01 for a $150,000 ADU, about $2,696 together, and $1,998.85 plus $1,724.51, about $3,723, for a $250,000 ADU. LADBS publishes a sample permit for a one-story detached ADU valued at $121,200 that shows how the real bill stacks up: a $986.40 permit subtotal, $256.46 electrical, $128.23 HVAC and $256.46 plumbing lines inside the combined permit, $204.66 plan check, planning and system surcharges, and then $6,227 in LAUSD school district fees, a $146 Dwelling Unit Construction Tax and a $219 Residential Development Tax, for a printed total of $8,800.20. School fees apply to ADUs larger than 500 square feet; the city's impact fees are charged only for ADUs of 750 square feet or more, and then in proportion to the primary house; park fees and the affordable housing linkage fee do not apply to ADUs. Card payments add 2.7 percent.
Size, Height, Parking and Setbacks
State law fixes the floor. A city may not cap an ADU below 850 square feet, or 1,000 square feet for more than one bedroom, and must allow at least an 800-square-foot unit with 4-foot side and rear setbacks; detached ADUs top out at 1,200 square feet and attached ones at 50 percent of the existing house. Height must be allowed to at least 16 feet, 18 feet within half a mile walking distance of a major transit stop, plus 2 feet for a matching roof pitch. No parking may be required within half a mile of transit, in a historic district, or for a conversion, and demolished garage spaces need not be replaced. Fire sprinklers are not required unless the house needs them, and detached new ADUs must have solar panels.
Who Files and What to Bring
A homeowner may sign as owner-builder; a hired contractor needs a CSLB B license, with trade licenses for any separately permitted service connections. Submit through ePlanLA with the plot plan, floor and framing plans, energy compliance forms and, for a conversion, the existing certificate of occupancy and permits. LADBS's sample permit went through Expanded Counter Plan Check, which the department completes in about 2 hours; the state 60-day clock is the outer limit. Inspections run groundwork, rough, insulation, drywall and final, and a certificate of occupancy is issued for the new unit.
How to Get a ADU Permit in Los Angeles
Confirm the site
Any residential lot with an existing or proposed house qualifies. Check ZIMAS for hillside, fire-zone or historic overlays that change the standards.
Choose the path
Custom plans, an LADBS pre-approved Standard Plan (site-specific review only), a conversion, or AB 2533 amnesty for a pre-2020 unpermitted unit.
Submit through ePlanLA
Plot plan, floor and framing plans, energy forms and existing permit records for conversions. City Planning clears zoning; the 60-day state clock starts when the application is complete.
Pay fees and pull the combined permit
About $2,696 for a $150,000 unit or $3,723 for $250,000 in permit and plan check, plus LAUSD school fees over 500 sq ft and construction taxes; 2.7 percent more by card.
Build, inspect, occupy
Groundwork, rough, insulation, drywall and final inspections, requested a day ahead before 2 PM; a certificate of occupancy is issued for the new unit.