ADU Contractors in Monrovia, CA — License-Verified Contractors
Every contractor below holds an active California license with an office of record in Monrovia, 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
203 license-verified contractors based in Monrovia — page 4 of 5
Pro - Tech Security Inc
C-10C-7Proficient Electric
C-10Quality Craft Home Improvement
BC-54R & C Construction Inc
BC-6R J L Electrical
C-10Radu Tom Construction
BC-33Raffi's Metal Design
BC-23Rapid Rhino Plumbing
Foothill Builders Inc
BC-36Revamp Solar Co
Revamp Energy Inc
BC-10C-46Ripple Plumbing
C-36Rocket Plumbing
C-36Rocket Plumbing Repair
Campos Robert
C-36Rod Construction Managers
Electra - Comm Inc
BC-10Rodas Restoration Specialty
BD-64Rokni Electric Company Inc
AC-10Rp Builder
BRudy's Plumbing
C-36S C Construction
BS F K Construction Company
BS H Plumbing Heating & Air Conditioning
C-20C-36S P Construction
BSan Gabriel Valley Habitat For Humanity Inc
BSarff Casey K
C-10Saxony Construction Corporation
BSaxony Design Build Inc
BSchaeffler Gary L
BSewer King Plumbing And Rooter
C-36Shine Construction Co
BSignal Alarm Co Inc
C-10Simplified Handyman Construction Services
BSirius Plumbing Inc
C-36Smith Kevin
BSmith Ryan Construction
BSouthern California Builders
BSouthland View Construction
BSouthwestern Clean Fuels Corp
AHAZSpaeth Construction Company
BStillwell Phillip
BStructures De Silva Inc
BSullivan Construction
BT N W Electric Inc
C-10Thomas Perry C Construction Inc
ATipping Development Inc
BToma Frank Construction Inc
BUnicon Group Inc The
ABC-51C-8USA Alarm Systems Inc
C-10C-7V M Developer Inc
BVersatile Rooter & Plumbing
C-36Walters Chris Construction
BData source: CSLB public records as of November 6, 2026 · Verify any license at CSLB