ADU Rules in Arcadia.
Local ADU regulations, permit fees, setback requirements, and typical timelines for Arcadia. Last updated 2026-05-27.
Arcadia ADU Requirements
Attached ADU: up to 25 ft
Arcadia has limited transit coverage; replacement parking generally required.
Design 4 weeks · Permit 6 weeks · Build 36 weeks
Plain-language summary
In Arcadia, 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 required for most projects. Typical permit fees range from $7,000 to $14,000. A typical project takes approximately ~11 months from design start to move-in, including 4 weeks of design, 6 weeks for permit review, and 36 weeks of construction.
⚠️ ADU rules change frequently. Always verify current requirements with the Arcadia Building & Safety Department before submitting plans. Official source →
What to Watch Out For
- Horse-keeping overlay zones (R-M zones) apply to parts of Arcadia; ADU placement must respect equestrian easements.
- Larger lot sizes are common — confirm ADU size limits relative to primary dwelling sq ft.
- Arcadia Unified and Temple City Unified school districts assess separate school impact fees.
How Long Does It Take to Get an ADU Permit in Arcadia?
Site study, floor plans, elevations, structural drawings.
Plan check, corrections, and permit issuance by Arcadia 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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