Find a License-Verified ADU Contractor
Every listing is a real California contractor with an active license checked against CSLB public data as of November 6, 2026: the general builders — A (General Engineering) and B (General Building), the classifications that can build an ADU — plus the key licensed trades ADU construction uses: C-10 Electrical, C-36 Plumbing, and C-5 Framing & Rough Carpentry.
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1 · Sourced from CSLBListings come from the Contractors State License Board's public license data — not ads or paid placements.
2 · Active licenses onlySuspended and expired licenses are filtered out of every listing, every refresh.
3 · Refreshed monthlyThis snapshot is current as of November 6, 2026. Verify any license live, free, at CSLB before you hire.
Mars Construction Industries Corp
ADU Cities' own design-build team
CSLB #1138550 · A · B · C-36 · C-20
Building ADUs across Los Angeles, Orange, Riverside, San Bernardino, San Diego & Ventura counties
Browse ADU Contractors by County
Los Angeles County32,520 license-verified contractorsBrowse cities →Orange County12,290 license-verified contractorsBrowse cities →Riverside County8,542 license-verified contractorsBrowse cities →San Bernardino County6,185 license-verified contractorsBrowse cities →San Diego County12,325 license-verified contractorsBrowse cities →Ventura County3,745 license-verified contractorsBrowse cities →Santa Barbara County1,865 license-verified contractorsBrowse cities →San Luis Obispo County2,123 license-verified contractorsBrowse cities →Kern County2,111 license-verified contractorsBrowse cities →Imperial County251 license-verified contractorsBrowse cities →
Before You Hire: Learn the ADU Rules
A license tells you a contractor is legal — the rules tell you what you can build. Read the guides, then hire with both in hand.