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ADU Builders in Placentia, CA

18 builders · ranked by Google rating and review volume · 9 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 Placentia homeowners who are comparing builders right now. Includes your logo, project photos, a direct call button and a link to your website.

Located in Orange County, Placentia had a 2020 Census population of about 51,824. We found 18 ADU builders and contractors that show up for Placentia homeowners on Google Maps, 1 of them based in the city itself. Their average Google rating is 4.9 stars. 12 market themselves specifically as ADU builders, and 3 mention garage conversions. 9 have a matched, active CSLB license shown with a verified badge. The top-rated by our review-weighted score are John Christopher Construction, Inc., Vision ADU and Orange County Construction ADU Contractor.

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.

#2

Vision ADU

5.0 (14 Google reviews)
✔ CSLB License Verified #1115842

1440 S State College Blvd #6h, Anaheim, CA 92806

Serves Placentia · based in Anaheim
ADU specialist
#10

ADUscale

5.0 (4 Google reviews)

528 W Hampshire Ave, Anaheim, CA 92805

Serves Placentia · based in Anaheim
ADU specialistHome builder
#15

KoBolt Construction

4.6 (11 Google reviews)
✔ CSLB License Verified #1024785

406 E Commonwealth Ave #3, Fullerton, CA 92832

Serves Placentia · based in Fullerton
Remodels & additionsHome builderGeneral contractor
#16

Apex Construction

3.7 (6 Google reviews)
✔ CSLB License Verified #1020301

Service-area business · La Habra

Serves Placentia · based in La Habra
ADU specialistRemodels & additionsGeneral contractor

Permits and pre-approved plans in Placentia

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

Planning an ADU in Placentia? Start here

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Placentia ADU FAQ

How many ADU builders serve Placentia?

Our directory lists 18 ADU builders and contractors that appear for Placentia on Google Maps, including companies based in nearby Orange County communities.

Do I need a permit to build an ADU in Placentia?

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

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 Placentia 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

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