ADU Contractors in Orange, CA — License-Verified Contractors
Every contractor below holds an active California license with an office of record in Orange, verified against CSLB public data as of November 6, 2026: general builders — A (General Engineering) and B (General Building), the classifications that can build an ADU — and the licensed trades ADU construction uses, C-10 Electrical, C-36 Plumbing and C-5 Framing & Rough Carpentry. Listings are alphabetical; the featured builder is labeled, never ranked.
ADU rules — setbacks, size limits, parking, and fees — are set by the local jurisdiction and change often. Before you hire, read the ADU permit process guide and the Southern California ADU cost guide, and verify any license free at CSLB.
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
752 license-verified contractors based in Orange — page 16 of 16
Zone 4 Systems Integration And Design
Paradigm Holdings Group LLC
C-10D-21D-24Data source: CSLB public records as of November 6, 2026 · Verify any license at CSLB