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ADU Builders in Costa Mesa, CA

103 builders · ranked by Google rating and review volume · 53 CSLB license verified

★ Featured ADU builder

Featured ADU builder — this spot is open

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

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Located in Orange County, Costa Mesa had a 2020 Census population of about 111,918. We found 103 ADU builders and contractors that show up for Costa Mesa homeowners on Google Maps, 11 of them based in the city itself. Their average Google rating is 4.9 stars. 27 market themselves specifically as ADU builders, and 4 mention garage conversions. 53 have a matched, active CSLB license shown with a verified badge. The top-rated by our review-weighted score are Ivy Builders Remodeling, DYM Builders Group and OC Builders Group.

In Orange County, HOA and design-standard questions come up often. State law voids CC&Rs that ban ADUs, but HOAs can still apply reasonable objective standards. Compact lots make attached units and garage conversions popular.

#3

OC Builders Group

5.0 (76 Google reviews)
✔ CSLB License Verified #1052090

600 W Santa Ana Blvd Ste 114-499, Santa Ana, CA 92701

Serves Costa Mesa · based in Santa Ana
General contractor
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#5

Builderwell Design & Build

5.0 (61 Google reviews)
✔ CSLB License Verified #1022234

220 Newport Center Dr #22, Newport Beach, CA 92660

Serves Costa Mesa · based in Newport Beach
Design-buildRemodels & additionsHome builderGeneral contractor
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#7

Seamless Construction Inc

5.0 (43 Google reviews)
✔ CSLB License Verified #1089475

4343 Von Karman Ave #150F, Newport Beach, CA 92660

Serves Costa Mesa · based in Newport Beach
Remodels & additionsHome builderGeneral contractor
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#10

Modernyze

5.0 (26 Google reviews)
✔ CSLB License Verified #1019812

2323 Main St, Irvine, CA 92614

Serves Costa Mesa · based in Irvine
Remodels & additionsHome builderGeneral contractor
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#11

Avalon Studio Design Build Corp

5.0 (26 Google reviews)
✔ CSLB License Verified #1101572

17081 Sims Lane Unit A, Huntington Beach, CA 92649

Serves Costa Mesa · based in Huntington Beach
Design-buildRemodels & additionsHome builderGeneral contractor
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#12

Look Wow Builders

5.0 (24 Google reviews)
✔ CSLB License Verified #1121005

1600 Dove St Ste 260, Newport Beach, CA 92660

Serves Costa Mesa · based in Newport Beach
Remodels & additionsHome builderGeneral contractor
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#14

HQ Remodeling & Design Inc

4.9 (70 Google reviews)
✔ CSLB License Verified #1041842

17011 Beach Blvd suite 900, Huntington Beach, CA 92647

Serves Costa Mesa · based in Huntington Beach
Remodels & additionsGeneral contractor
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#15

Anastasi Builders

5.0 (23 Google reviews)
✔ CSLB License Verified #1086383

8581 St Augustine Dr, Huntington Beach, CA 92646

Serves Costa Mesa · based in Huntington Beach
General contractor
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#20

WallStar Design & Build

5.0 (19 Google reviews)

21030 Pacific City Cir Unit 3207, Huntington Beach, CA 92648

Serves Costa Mesa · based in Huntington Beach
Design-buildRemodels & additionsGeneral contractor
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#24

Vulcon Builders

5.0 (18 Google reviews)
✔ CSLB License Verified #1128480

2082 Michelson Dr #100, Irvine, CA 92612

Serves Costa Mesa · based in Irvine
Remodels & additionsHome builderGeneral contractor
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#26

OC Quality Builders

4.9 (30 Google reviews)
✔ CSLB License Verified #1148925

22981 Triton Way Unit C, Laguna Hills, CA 92653

Serves Costa Mesa · based in Laguna Hills
Remodels & additionsHome builderGeneral contractor
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#27

Titan Framing, Inc

5.0 (15 Google reviews)
✔ CSLB License Verified #1115866

9114 Adams Ave #171, Huntington Beach, CA 92646

Serves Costa Mesa · based in Huntington Beach
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#41

VICOREL

5.0 (9 Google reviews)
✔ CSLB License Verified #1143460

2372 Morse Ave Ste 746, Irvine, CA 92614

Serves Costa Mesa · based in Irvine
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#46

Innovative Craftsmanship

5.0 (7 Google reviews)
✔ CSLB License Verified #1023122

120 Newport Center Dr Ste 7012, Newport Beach, CA 92660

Serves Costa Mesa · based in Newport Beach
Remodels & additionsHome builderGeneral contractor
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#47

Kash Construction Inc

5.0 (7 Google reviews)
✔ CSLB License Verified #1028459

23301 Ridge Rte Dr, Laguna Hills, CA 92653

Serves Costa Mesa · based in Laguna Hills
Remodels & additionsGeneral contractor
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#52

Dv construction

5.0 (4 Google reviews)
✔ CSLB License Verified #1116638

10055 Lampson Ave, Garden Grove, CA 92840

Serves Costa Mesa · based in Garden Grove
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#53

Tech LA Builder

5.0 (4 Google reviews)
✔ CSLB License Verified #1097275

20381 Lake Forest Dr, Lake Forest, CA 92630

Serves Costa Mesa · based in Lake Forest
General contractor
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#55

MLR Construction Co

5.0 (4 Google reviews)
✔ CSLB License Verified #1108801

Service-area business · Fountain Valley

Serves Costa Mesa · based in Fountain Valley
Remodels & additionsHome builderGeneral contractor
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#57

Plus Home ADU

5.0 (3 Google reviews)
✔ CSLB License Verified #1062063

Service-area business · Aliso Viejo

Serves Costa Mesa · based in Aliso Viejo
ADU specialistRemodels & additionsHome builderGeneral contractor
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#64

CCS ADU Services

5.0 (2 Google reviews)

Service-area business · San Clemente

Serves Costa Mesa · based in San Clemente
ADU specialistHome builder
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#67

Pelican ADU Builders

5.0 (2 Google reviews)
✔ CSLB License Verified #1106515

1924 Barranca Pkwy Unit 1, Irvine, CA 92606

Serves Costa Mesa · based in Irvine
ADU specialistGeneral contractor
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#69

Stone Development Inc

5.0 (2 Google reviews)
✔ CSLB License Verified #1146382

1 Jenner Ste 150, Irvine, CA 92618

Serves Costa Mesa · based in Irvine
Remodels & additionsHome builderGeneral contractor
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#70

Romans Builders

5.0 (2 Google reviews)
✔ CSLB License Verified #1149246

522 19th St, Huntington Beach, CA 92648

Serves Costa Mesa · based in Huntington Beach
Home builder
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#72

White Lotus Homes

5.0 (2 Google reviews)
✔ CSLB License Verified #1124683

650 Town Center Dr #1670, Costa Mesa, CA 92626

Based in Costa Mesa
Home builder
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#77

DWELLO ADU INC

5.0 (1 Google reviews)

23361 Madero Ste 235, Mission Viejo, CA 92691

Serves Costa Mesa · based in Mission Viejo
ADU specialistGeneral contractor
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#80

Epic Remodeling

4.5 (16 Google reviews)
✔ CSLB License Verified #1095347

17801 Main St, Irvine, CA 92614

Serves Costa Mesa · based in Irvine
Remodels & additions
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#81

LMX Builders

4.5 (15 Google reviews)
✔ CSLB License Verified #949201

1 Hollinwood, Irvine, CA 92618

Serves Costa Mesa · based in Irvine
Remodels & additionsGeneral contractor
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#88

Skye Construction

No rating yet (0 Google reviews)
✔ CSLB License Verified #1068435

1302 E Hunter Ave #C, Santa Ana, CA 92705

Serves Costa Mesa · based in Santa Ana
General contractor
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#89

Orange Innovation

No rating yet (0 Google reviews)
✔ CSLB License Verified #832810

15122 Starboard St, Garden Grove, CA 92843

Serves Costa Mesa · based in Garden Grove
General contractor
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#91

Rigi Home & Garden Design LLC

No rating yet (0 Google reviews)
✔ CSLB License Verified #1161845

Service-area business · Newport Beach

Serves Costa Mesa · based in Newport Beach
Garage conversionsRemodels & additionsHome builderGeneral contractor
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#92

J&R ADU

No rating yet (0 Google reviews)

Service-area business · Fountain Valley

Serves Costa Mesa · based in Fountain Valley
ADU specialistPrefab / modularHome builder
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#94

ADU-BUILDS

No rating yet (0 Google reviews)
✔ CSLB License Verified #1150636

Service-area business · Newport Beach

Serves Costa Mesa · based in Newport Beach
ADU specialist
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#98

OCADUSTUDIO

No rating yet (0 Google reviews)
✔ CSLB License Verified #1155045

13251 Pinto Rd, Garden Grove, CA 92843

Serves Costa Mesa · based in Garden Grove
ADU specialistGeneral contractor
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#99

Shore-Tech Builders LLC

No rating yet (0 Google reviews)
✔ CSLB License Verified #856735

8111 Wadebridge Cir, Huntington Beach, CA 92646

Serves Costa Mesa · based in Huntington Beach
Remodels & additionsHome builder
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Permits and pre-approved plans in Costa Mesa

ADU permits in Costa Mesa go through the city's building or planning department. Under AB 1332, every California city and county had to set up a pre-approved ADU plan program by January 1, 2025, so ask Costa Mesa whether it has approved plans you can use. See our pre-approved plans guide and California ADU law summary.

Planning an ADU in Costa Mesa? Start here

Two-Story and Above-Garage ADUs in California: Height Rules, Costs and DesignHow Long Does It Take to Build an ADU in Southern California?ADU Rental Income and Property Taxes in California: What to ExpectHow to Choose an ADU Builder in Southern California: 15-Point Checklist

All ADU guides →

Costa Mesa ADU FAQ

How many ADU builders serve Costa Mesa?

Our directory lists 103 ADU builders and contractors that appear for Costa Mesa on Google Maps, including companies based in nearby Orange County communities.

Do I need a permit to build an ADU in Costa Mesa?

Yes. ADUs need a building permit from the City of Costa Mesa, which must approve or deny a complete application within 60 days under state law. Many cities also offer pre-approved plans that speed up review.

How much does an ADU cost in Costa Mesa?

Most Southern California detached ADUs land around $350 to $550 per square foot all-in, garage conversions around $200 to $350, and JADUs around $50,000 to $150,000. Use our ADU cost estimator and get three itemized bids.

How are Costa Mesa ADU builders ranked here?

By Google rating weighted by the number of reviews, so a 4.9 with 200 reviews ranks above a 5.0 with 3. Featured placements are clearly labeled and don't affect the organic ranking.

Nearby cities in Orange County

Anaheim 114Santa Ana 97Irvine 107Huntington Beach 88Garden Grove 97Fullerton 23Orange 95Mission Viejo 59Westminster 53Lake Forest 60Newport Beach 96Buena Park 52
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