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ADU Builders in Simi Valley, CA

100 builders · ranked by Google rating and review volume · 51 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 Simi Valley 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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With roughly 126,356 residents at the 2020 Census, Simi Valley is one of Ventura County's established communities. We found 100 ADU builders and contractors that show up for Simi Valley homeowners on Google Maps, 3 of them based in the city itself. Their average Google rating is 4.9 stars. 30 market themselves specifically as ADU builders, and 10 mention garage conversions. 51 have a matched, active CSLB license shown with a verified badge. The top-rated by our review-weighted score are Olympia Construction, LA Family Builders Inc and GreatBuildz.

Ventura County mixes coastal and inland communities. Coastal parcels may need a coastal permit, and fire-hazard zones can add requirements for siting and materials.

#3

GreatBuildz

5.0 (98 Google reviews)

17141 Ventura Blvd, Encino, CA 91316

Serves Simi Valley · based in Encino
Garage conversionsRemodels & additionsHome builderGeneral contractor
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#4

ADU Conversion

5.0 (86 Google reviews)

Service-area business · Simi Valley

Serves Simi Valley · based in Simi Valley
ADU specialistRemodels & additionsGeneral contractor
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#5

ODM Construction

5.0 (71 Google reviews)
✔ CSLB License Verified #1069960

28720 Roadside Dr #310, Agoura Hills, CA 91301

Serves Simi Valley · based in Agoura Hills
Remodels & additionsHome builderGeneral contractor
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#10

SOUL Builders

5.0 (55 Google reviews)
✔ CSLB License Verified #1103425

18163 Arminta St, Reseda, CA 91335

Serves Simi Valley · based in Reseda
General contractor
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#11

Eden Builders

5.0 (54 Google reviews)
✔ CSLB License Verified #891510

4616 Santa Lucia Dr, Woodland Hills, CA 91364

Serves Simi Valley · based in Woodland Hills
Remodels & additionsHome builderGeneral contractor
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#12

Flip It Homes Inc.

5.0 (51 Google reviews)
✔ CSLB License Verified #1043456

20501 Ventura Blvd #135, Woodland Hills, CA 91364

Serves Simi Valley · based in Woodland Hills
Home builder
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#19

X Buildup

5.0 (32 Google reviews)
✔ CSLB License Verified #1075868

21825 Erwin St Ste 1076, Woodland Hills, CA 91367

Serves Simi Valley · based in Woodland Hills
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#20

ADU Concepts

5.0 (30 Google reviews)
✔ CSLB License Verified #1018294

18375 Ventura Blvd, Tarzana, CA 91356

Serves Simi Valley · based in Tarzana
ADU specialist
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#21

Preferred Home Builders

4.9 (135 Google reviews)
✔ CSLB License Verified #773147

21204 Vanowen St, Canoga Park, CA 91303

Serves Simi Valley · based in Canoga Park
Garage conversionsRemodels & additionsHome builderGeneral contractor
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#24

MY Home Builders

4.9 (99 Google reviews)
✔ CSLB License Verified #1002927

20720 Ventura Blvd Unit 280, Woodland Hills, CA 91364

Serves Simi Valley · based in Woodland Hills
Remodels & additionsHome builderGeneral contractor
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#26

Adar Builders Inc

4.9 (67 Google reviews)
✔ CSLB License Verified #1051859

7673 Winnetka Ave, Winnetka, CA 91306

Serves Simi Valley · based in Winnetka
Remodels & additionsHome builderGeneral contractor
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#27

MASTER IN DESIGN

4.9 (62 Google reviews)
✔ CSLB License Verified #979219

6011 Reseda Blvd, Tarzana, CA 91356

Serves Simi Valley · based in Tarzana
Remodels & additionsHome builderGeneral contractor
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#29

ITM Construction

5.0 (21 Google reviews)
✔ CSLB License Verified #1033834

20329 Cantara St, Winnetka, CA 91306

Serves Simi Valley · based in Winnetka
Remodels & additionsGeneral contractor
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#30

360 Builders

5.0 (20 Google reviews)

19562 Ventura Blvd #230, Tarzana, CA 91356

Serves Simi Valley · based in Tarzana
Home builderGeneral contractor
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#31

Nobel Builders

5.0 (19 Google reviews)
✔ CSLB License Verified #1105489

21402 Wyandotte St, Canoga Park, CA 91303

Serves Simi Valley · based in Canoga Park
Remodels & additionsHome builderGeneral contractor
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#32

ATARI Home Builders

4.9 (44 Google reviews)
✔ CSLB License Verified #1088740

19720 Ventura Blvd e1, Woodland Hills, CA 91364

Serves Simi Valley · based in Woodland Hills
Remodels & additionsHome builderGeneral contractor
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#33

CONSTRUCTION BY MAYA INC.

4.9 (41 Google reviews)
✔ CSLB License Verified #1021375

4500 Park Granada UNIT 202, Calabasas, CA 91302

Serves Simi Valley · based in Calabasas
Remodels & additionsHome builderGeneral contractor
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#34

DVB CONSTRUCTION

5.0 (18 Google reviews)
✔ CSLB License Verified #1112397

Service-area business · Agoura Hills

Serves Simi Valley · based in Agoura Hills
Remodels & additionsGeneral contractor
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#35

Upfront Remodeling

5.0 (18 Google reviews)
✔ CSLB License Verified #1101426

5676 Lindley Ave, Encino, CA 91316

Serves Simi Valley · based in Encino
Remodels & additionsHome builderGeneral contractor
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#36

KōRA Design Build

5.0 (16 Google reviews)

6980 N Platt Ave Unit 1 Studio, West Hills, CA 91307

Serves Simi Valley · based in West Hills
Design-buildRemodels & additionsHome builderGeneral contractor
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#40

National Development Group

4.9 (25 Google reviews)
✔ CSLB License Verified #1080447

2955 E Hillcrest Dr #129, Westlake Village, CA 91362

Serves Simi Valley · based in Westlake Village
Remodels & additionsHome builderGeneral contractor
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#43

Built To Perfection, Inc.

4.8 (119 Google reviews)
✔ CSLB License Verified #837987

21201 Victory Blvd Unit 235, Canoga Park, CA 91303

Serves Simi Valley · based in Canoga Park
Remodels & additionsHome builderGeneral contractor
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#44

Mayan Home Builders

5.0 (12 Google reviews)
✔ CSLB License Verified #1107341

3625 E Thousand Oaks Blvd, Thousand Oaks, CA 91362

Serves Simi Valley · based in Thousand Oaks
Remodels & additionsHome builderGeneral contractor
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#46

H&A My Design, Inc.

4.8 (78 Google reviews)
✔ CSLB License Verified #1110519

6723 Variel Ave, Canoga Park, CA 91303

Serves Simi Valley · based in Canoga Park
Remodels & additionsGeneral contractor
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#54

Westlake ADU LLC

5.0 (9 Google reviews)
✔ CSLB License Verified #1119001

10720 Haskell Ave, Granada Hills, CA 91344

Serves Simi Valley · based in Granada Hills
ADU specialistGeneral contractor
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#63

Ohana Remodeling

5.0 (7 Google reviews)
✔ CSLB License Verified #1101325

6735 Glade Ave, Los Angeles, CA 91303

Serves Simi Valley · based in Los Angeles
Remodels & additionsGeneral contractor
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#67

Pearl Remodeling

4.7 (72 Google reviews)
✔ CSLB License Verified #955824

6803 Yarmouth Ave, Reseda, CA 91335

Serves Simi Valley · based in Reseda
Remodels & additionsHome builderGeneral contractor
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#71

JLC Home Remodeling

5.0 (5 Google reviews)
✔ CSLB License Verified #1024612

5308 Derry Ave, Agoura Hills, CA 91301

Serves Simi Valley · based in Agoura Hills
Remodels & additionsGeneral contractor
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#74

MH CONSTRUCTION INC

5.0 (4 Google reviews)
✔ CSLB License Verified #1148205

19223 Chase St, Northridge, CA 91324

Serves Simi Valley · based in Northridge
General contractor
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#81

GNK Construction

4.7 (12 Google reviews)
✔ CSLB License Verified #1052060

6618 Smoke Tree Ave, Oak Park, CA 91377

Serves Simi Valley · based in Oak Park
General contractor
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#83

ADU XPERT

5.0 (2 Google reviews)

19849 Nordhoff St, Northridge, CA 91324

Serves Simi Valley · based in Northridge
ADU specialistHome builder
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#86

Level Up Contractor Inc.

4.6 (37 Google reviews)
✔ CSLB License Verified #1053375

6700 Fallbrook Ave #224b, West Hills, CA 91307

Serves Simi Valley · based in West Hills
Garage conversionsRemodels & additionsHome builderGeneral contractor
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#91

ADU360

5.0 (1 Google reviews)

15500 Erwin St #2002, Van Nuys, CA 91411

Serves Simi Valley · based in Van Nuys
ADU specialist
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Permits and pre-approved plans in Simi Valley

ADU permits in Simi Valley 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 Simi Valley whether it has approved plans you can use. See our pre-approved plans guide and California ADU law summary.

Planning an ADU in Simi Valley? Start here

ADU Rental Income and Property Taxes in California: What to ExpectThe ADU Permit Process in California: Step by Step (2026)JADU vs ADU in California: Size, Rules, Cost and Which to BuildGarage Conversion ADU Cost in Southern California (and What Drives It)

All ADU guides →

Simi Valley ADU FAQ

How many ADU builders serve Simi Valley?

Our directory lists 100 ADU builders and contractors that appear for Simi Valley on Google Maps, including companies based in nearby Ventura County communities.

Do I need a permit to build an ADU in Simi Valley?

Yes. ADUs need a building permit from the City of Simi Valley, 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 Simi Valley?

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 Simi Valley 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 Ventura County

Oxnard 31Thousand Oaks 122Ventura 26Camarillo 48Moorpark 8Santa Paula 5Port Hueneme 5
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