ADU Rules in Brentwood.
Local ADU regulations, permit fees, setback requirements, and typical timelines for Brentwood (City of Los Angeles). Last updated 2026-05-27.
Brentwood ADU Requirements
Attached ADU: up to 25 ft
Design 4 weeks · Permit 8 weeks · Build 40 weeks
Plain-language summary
In Brentwood (governed by the City of 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 City of Los Angeles Building & Safety Department before submitting plans. Official source →
What to Watch Out For
- Brentwood is a neighborhood within the City of Los Angeles — all LADBS rules apply.
- Brentwood Homeowners Alliance areas may have CC&Rs with design standards.
- Areas near the Brentwood hills may fall within VHFHSZ — verify your lot before design.
How Long Does It Take to Get an ADU Permit in Brentwood?
Site study, floor plans, elevations, structural drawings.
Plan check, corrections, and permit issuance by City of 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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