ADU Rules in Los Angeles.
Local ADU regulations, permit fees, setback requirements, and typical timelines for Los Angeles. Last updated 2026-05-27.
Los Angeles ADU Requirements
Fire Zone 1 and hillside properties may require additional setbacks.
18 ft permitted within ½ mile of a major transit stop.
Detached ADU may be up to 50% of primary dwelling sq ft, not to exceed 1,200 sq ft. Attached ADU limited to 50% of primary dwelling.
Replacement parking not required. Most of LA is within ½ mile of transit.
Fees include plan check, permit issuance, school fees, and fire/safety review. Fees vary significantly by size and location.
Design 4 weeks · Permit 8 weeks · Build 40 weeks
Plain-language summary
In Los Angeles, a detached ADU requires a minimum 4-foot side setback and 4-foot rear setback. The maximum height for a detached ADU is 16 feet, while an attached ADU may be up to 25 feet. The maximum size for a detached ADU is 1,200 sq ft; a Junior ADU (JADU) is limited to 500 sq ft. Replacement parking is not required for most projects. Typical permit fees range from $10,000 to $22,000. A typical project takes approximately ~12 months from design start to move-in, including 4 weeks of design, 8 weeks for permit review, and 40 weeks of construction.
⚠️ ADU rules change frequently. Always verify current requirements with the Los Angeles Building & Safety Department before submitting plans. Official source →
What to Watch Out For
- ADU Standard Plan Program available — pre-approved plans can reduce permit review time by 4–6 weeks.
- Very High Fire Hazard Severity Zone (VHFHSZ) properties require Class A roofing, fire-resistant exterior materials, and ember-resistant vents.
- Coastal Zone properties along the Pacific Coast corridor may require a Coastal Development Permit from the California Coastal Commission.
- Historic Preservation Overlay Zones (HPOZs) require design review for any new structure visible from the public right-of-way.
- Owner-occupancy not required (AB 976, effective Jan 2023).
How Long Does It Take to Get an ADU Permit in Los Angeles?
Site study, floor plans, elevations, structural drawings.
Plan check, corrections, and permit issuance by Los Angeles Building & Safety.
Foundation, framing, MEP rough-in, finishes, final inspection.
A licensed engineer on your lot, free.
30 minutes. We walk the property, figure out what's feasible, and answer any questions you have.
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