Floworx Plumbing & Rooter
We The People Plumbing & Drains LLC
C-36Every 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 6 of 16
We The People Plumbing & Drains LLC
C-36Fontaine Weatherproofing LLC
BC-39C-43Sudduth Construction Inc
BC-39H Z S Engineering Inc
ABC-8Hanna Construction Inc
BC-8Data source: CSLB public records as of November 6, 2026 · Verify any license at CSLB