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Does your project need a permit?
Choose your state and the project you're planning. WikEst shows the permit requirement, issuing authority, typical fee and timeline, and a go / no-go — each linked to its official source.
🏠 Accessory Dwelling Unit (ADU) in California
Permit requiredGenerally allowedcity authority
Typical fee
Permit and plan-check fees set by the local jurisdiction; state law limits impact fees on ADUs. Verify with the city building department.
Typical timeline
~3–6 months for full plan review; many cities offer pre-approved plans or over-the-counter review.
Setback
State standard: 4 ft side/rear setback; local front/side yards still apply.
Exempt if
By-right up to 1,200 sq ft (≤800 sq ft for a 1-bedroom unit) under state law.
Exempt criteria
None — ADUs always require a building permit.
State law (Gov. Code §65852.2) requires cities to approve ADUs ministerially by right in most zones; local design review is limited to objective standards. Local fees, setbacks, and coastal/historic overlays still apply.
Sources: CA Dept. of Housing & Community Development — Accessory Dwelling Units (ADU/JADU) · Los Angeles Dept. of Building & Safety
Representative cities for California: Los Angeles, San Francisco, San Diego. This is guidance, not legal advice — confirm with the local building department.