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Southern California's ADU builder directory

Find the best ADU builders in Southern California

Compare 1,752 ADU builders across 162 cities in LA, Orange, San Diego, Riverside, San Bernardino and Ventura counties. Real Google ratings, CSLB license badges, and specialists in garage conversions, JADUs and prefab.

Los AngelesSan DiegoLong BeachAnaheimRiversideSanta AnaIrvineChula Vista
1,752ADU builders
162SoCal cities
900CSLB licenses matched
37,998Google reviews analyzed
★ Featured ADU builder

Featured ADU builder — this spot is open

Put your ADU company at the top of this page, in front of Southern California homeowners who are comparing builders right now. Includes your logo, project photos, a direct call button and a link to your website.

📞 Call 424-298-3600💬 Text 424-298-3600

Browse by ADU type

Detached ADUAttached ADUGarage conversionJunior ADU (JADU)Prefab / modularTwo-story / above-garage

Browse by county

Los Angeles County66 citiesOrange County30 citiesSan Diego County16 citiesRiverside County23 citiesSan Bernardino County19 citiesVentura County8 cities

Top SoCal cities for ADU builders

Los Angeles118 builders · Los Angeles CountySan Diego120 builders · San Diego CountyLong Beach119 builders · Los Angeles CountyAnaheim114 builders · Orange CountyRiverside54 builders · Riverside CountySanta Ana97 builders · Orange CountyIrvine107 builders · Orange CountyChula Vista86 builders · San Diego CountySanta Clarita27 builders · Los Angeles CountySan Bernardino51 builders · San Bernardino CountyMoreno Valley8 builders · Riverside CountyFontana83 builders · San Bernardino CountyOxnard31 builders · Ventura CountyHuntington Beach88 builders · Orange CountyGlendale117 builders · Los Angeles CountyOntario54 builders · San Bernardino CountyRancho Cucamonga31 builders · San Bernardino CountyOceanside56 builders · San Diego CountyLancaster12 builders · Los Angeles CountyGarden Grove97 builders · Orange CountyPalmdale12 builders · Los Angeles CountyCorona32 builders · Riverside CountyPomona67 builders · Los Angeles CountyEscondido110 builders · San Diego County

All 162 cities →

ADU cost estimatorBallpark by type and square footage, using sourced SoCal ranges.ADU financingHELOC vs cash-out refi vs construction loans, plus CalHFA grant status.California ADU lawsSize, height, setbacks, parking, fees and the 2026 changes, with citations.Pre-approved plansFree and low-cost city and county plan programs across SoCal.

Highest-rated ADU builders in Southern California

Ranked by Google rating weighted by review count (minimum 20 reviews).

Homeowners reviewing ADU plans (illustration)

How to choose an ADU builder

  1. Verify the CSLB license. Look for an active B General Building license, and confirm workers' comp.
  2. Ask who handles design and permits. Design-build firms do it all. Others need your architect's plans.
  3. Compare three itemized bids with the same size, finishes and utility scope.
  4. Check the payment schedule. Down payments are capped at $1,000 or 10%.
  5. Visit a finished ADU and talk to past clients.
Read the full guide

ADU guides for Southern California homeowners

AB 1033: Can You Sell an ADU Separately in California?How Much Does It Cost to Build an ADU in Southern California?The ADU Permit Process in California: Step by Step (2026)ADU Rental Income and Property Taxes in California: What to ExpectGarage Conversion ADU Cost in Southern California (and What Drives It)How Long Does It Take to Build an ADU in Southern California?How to Choose an ADU Builder in Southern California: 15-Point ChecklistJADU vs ADU in California: Size, Rules, Cost and Which to BuildHow to Legalize an Unpermitted ADU in California (AB 2533)Prefab and Modular ADUs in California: Real Costs, Permits and PitfallsSB 9 vs ADU: Lot Splits, Duplexes and Backyard Units in CaliforniaTwo-Story and Above-Garage ADUs in California: Height Rules, Costs and Design
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