Best ADU Builders in Huntington Beach, CA
Compare vetted, CSLB license-verified ADU builders and ADU contractors in Huntington Beach. The average cost to build an ADU in Huntington Beach is $250–$400 per square foot. Top-rated builders include HQ Remodeling & Design Inc, Acton ADU, ADU West Coast.
Every builder below is CSLB license-verified, bonded, and insured — vetted before they ever reach a homeowner. Browse ratings and real reviews, compare starting prices, or let us match you with the best fit for your lot and budget. It's free; we're paid by the builders, not you.
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What kind of ADU are you planning?
ADU activity in Huntington Beach
ADU projects in Huntington Beach commonly budget $250-$400 per sq ft, or about $200,000-$320,000 for an 800 sq ft ADU, before site conditions, utility upgrades, and finish choices.
Showing 12 of 12 builders in Huntington Beach, CA
Last updated July 16, 2026
License VerifiedHQ Remodeling & Design Inc
Serving Huntington Beach, CA · Huntington Beach, CA
“I was so tired of our old kitchen so I decided to look for the best local designer to make me a new kitchen. I found HQ, they had great reviews and local reputa…”— KOMA Expand your limits
Pricing on request
CSLB-verified B contractor in Huntington Beach, CA.
License VerifiedActon ADU
Serving Huntington Beach, CA · Campbell, CA
“We had a great experience working with Acton ADU on our ADU project, and I want to give a special shoutout to Sandro. Sandro was fantastic from start to finish—…”— N K
Pricing on request
A California general building contractor licensed since 1992, serving the LA market statewide.
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License VerifiedADU West Coast
Serving Huntington Beach, CA · Seal Beach, CA
“Recently, I’ve had the opportunity to work with Cameron and the ADU West Coast team on a new home project. I am extremely impressed with their services that oth…”— Max “MaxMufc2018” T
Pricing on request
CSLB-verified B contractor in Seal Beach, CA.
License VerifiedSuperior ADUs - ADU Builders Orange County
Serving Huntington Beach, CA · Irvine, CA
“Superior ADUs – A Top-Tier Experience from Start to Finish! I can't say enough great things about Superior ADUs! From the very first consultation to the final…”— Lisa Dumont
Pricing on request
CSLB-verified B contractor in Irvine, CA.
License VerifiedAvalon Studio Design Build Corp
Serving Huntington Beach, CA · Huntington Beach, CA
“After working with several contractors, choosing Avalon Studio made all the difference. From the start, their approach felt truly professional, and Eddie’s leve…”— Ronen Malka
Pricing on request
CSLB-verified B contractor in Huntington Beach, CA.
License VerifiedPartner Construction, Inc
Serving Huntington Beach, CA · Huntington Beach, CA
“Michael and the team at Partner Construction did a great job on our home remodel. The process was smooth, and they were organized, responsive, and easy to work…”— Kate Callan
Pricing on request
CSLB-verified B contractor in Huntington Beach, CA.
License VerifiedVilla Homes
Serving Huntington Beach, CA · San Francisco, CA
“Excellent job! The Villa crew from start to finish nothing short of professional. Foundation, home delivery, finish work etc top notch. I would recommend Vill…”— M Ferreira
Pricing on request
Tech-enabled prefab ADU builder delivering turnkey backyard homes across California.
Orange County Construction ADU Contractor
Serving Huntington Beach, CA · Anaheim, CA
“We purchased a Westminster, CA home that was a fixer upper with plans to fully renovate before moving in. Orange County Construction was recommended to us from…”— Daowyw Trosyao
Pricing on request
CSLB-verified B contractor in Anaheim, CA.
License VerifiedADU Designers & Builders
Serving Huntington Beach, CA · Brea, CA
“Super happy with how my new place turned out! The crew was easy to work with, kept me updated, and finished per schedule. The quality is solid and everything lo…”— Vina
Pricing on request
CSLB-verified B contractor in Brea, CA.
License VerifiedNestadu
Serving Huntington Beach, CA · Mill Valley, CA
“Nestadu did a great job on my backyard ADU. Their team was professional, and the final result looks fantastic—well-built and blends in nicely with my home. Pric…”— Stephen Reid
Pricing on request
Custom and prefab ADUs for California homeowners — design, permit, and build, turnkey.
License VerifiedADU Certified
Serving Huntington Beach, CA · Long Beach, CA
“Dimas was great. He was affordable. Our ADU looks so luxurious. All our friends and family love it. Dimas runs a clean jobsite. We are very pleased with how the…”— Garrett Stack
Pricing on request
CSLB-verified B contractor in Long Beach, CA.
License VerifiedCustom ADU Builder
Serving Huntington Beach, CA · Fullerton, CA
“I had an excellent experience working with Custom ADU Builder. From start to finish the project was smooth and professional. Dennis was incredibly responsive -…”— Cecilia Lacuesta
Pricing on request
CSLB-verified B contractor in Fullerton, CA.
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Frequently Asked Questions
- How much does it cost to build an ADU in Huntington Beach, CA?
- In Huntington Beach, ADUs typically run $250–$400 per square foot all-in. A detached 800 sq ft unit commonly lands between $230k and $340k depending on finishes, site conditions, and utility connections. Garage conversions are the most affordable path, often under $180k.
- How long does it take to build an ADU in Huntington Beach?
- Plan to budget 6–12 months end to end. California law caps ADU plan check at 60 days for compliant designs, and construction usually takes 4–8 months after permits are issued.
- Do I need a permit to build an ADU in Huntington Beach?
- Yes. All ADUs require a building permit, but California mandates ministerial (non-discretionary) approval for compliant units, so there's no public hearing or design review. Your builder typically pulls the permit on your behalf.
- How do I choose a builder in Huntington Beach?
- Confirm the contractor holds an active CSLB license, is bonded and insured, and has built ADUs in Huntington Beach specifically. Every builder in this directory is license-verified. Use "Get a Quote" to be matched with the best fit for your lot and budget.
ADU costs in Huntington Beach: city vs. metro vs. state
Building an ADU in Huntington Beach runs roughly $250–$400 per square foot all-in. Here's how the city benchmarks against the broader metro and statewide averages.
| Area | Avg. cost / sq ft | Typical 800 sq ft ADU |
|---|---|---|
| Huntington Beach | $250–$400 | $200,000–$320,000 |
| Huntington Beach metro | ~$320 | ~$256,000 |
| California (CA) | ~$330 | ~$264,000 |
Cost by ADU type in Huntington Beach
| ADU type | Typical size | Project cost | Timeline |
|---|---|---|---|
| Detached ADU | 600–1,200 sq ft | $180,000–$420,000 | 8–12 months |
| Attached ADU | 400–800 sq ft | $140,000–$300,000 | 6–10 months |
| Garage Conversion | 400–600 sq ft | $90,000–$180,000 | 4–7 months |
| JADU (Junior ADU) | ≤ 500 sq ft | $60,000–$140,000 | 3–6 months |
ADU rules & permits in Huntington Beach, CA
Local ADU permitting in Huntington Beach follows California state ADU law, which caps plan-check at 60 days for compliant units. Confirm setbacks, height, and parking rules with the local building department.
| Jurisdiction | Permit timeline | Permit fees | Notes |
|---|---|---|---|
| Huntington Beach (independent city) | 60 days max by CA statute | Set by local ordinance | Permits are issued by the Huntington Beach building department, not the City of Los Angeles |
| Statewide (CA) | 60 days max by statute | Varies | Ministerial approval; owner-occupancy requirement waived through 2030 |
Financing your ADU in Huntington Beach
Common ADU funding paths include renovation and construction loans, a HELOC, or a cash-out refinance. ADU-specific lenders underwrite against after-build value, which often unlocks more than a standard HELOC.
Construction / renovation loan
Funds released in draws as the build hits milestones; underwritten against after-build value.
HELOC / home equity
Borrow against existing equity. Fast to set up if you have 20%+ equity.
Cash-out refinance
Replace your mortgage and pull equity as cash — best when rates are favorable.
ADU-specific lenders
RenoFi and similar lenders underwrite the projected value the ADU adds, often unlocking more.
Pre-ADU Checkup — $499 — Get finalized permits, a pre-ADU checklist, and an on-site feasibility visit. Homeowners save $1,000s by doing this before engaging a contractor.