ADU Contractors in Orange County, CA
12,290 active, license-verified contractors with an office of record in Orange County — general builders (A & B) and the licensed trades that build ADUs (C-10 electrical, C-36 plumbing, C-5 framing). Pick your city, or search directly.
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
Orange County packs 34 incorporated cities plus unincorporated communities like Trabuco Canyon, Silverado, and Ladera Ranch — 46 places in all — into California's third-most-populous county, and ADU demand runs from coastal lots in Newport Beach and Dana Point to family compounds in Santa Ana, Anaheim, and Garden Grove. This directory lists 12,290 active, license-verified contractors with an office of record in the county — general builders (A and B) plus the licensed trades ADU projects use (C-10 electrical, C-36 plumbing, C-5 framing).
Every Orange County city writes its own ADU ordinance under state law, so setbacks, parking, and fees in Irvine are not the rules in Fullerton. Check the license here, then check your city's rules before you sign anything — the permit process guide shows what to ask for.