Free · instant · no obligation
Get your instant ADU cost estimate for Orange County.
Most detached Orange County ADUs run $245K–$440K+. Where does yours land? ~30 seconds, tap through.
Avorino design · 600 sq ft · 1 bed
An original Avorino design drawn for answers like yours, not a unit we have built yet.
General-B License #1107538 · 7+ yrs · 37 OC cities & communities · 4.8★ from 35+ homeowners
Prefer to talk? (714) 900-3676How we build
Design visualizationShown on the Bellecielo, one of Avorino's named ADU plans: 830 sqft · 2 bedrooms · 2 bathrooms.See the ADU plans
A clear, proven process from concept to keys.
Avorino actively involves clients throughout the build.
- 01 / 07
Design your vision
From floor plans to finishes, we help you shape every detail. We listen first, then design with your priorities in mind.
- 02 / 07
Engineering + drawings
Architecture, structural engineering, and Title 24 calculations integrated from day one. Real-time cost visibility throughout.
- 03 / 07
Get building permits
We handle the city, the paperwork, and the engineering. You focus on the exciting parts while we clear the path to break ground.
- 04 / 07
Pick your finishes
Cabinetry, stone, tile, fixtures, and appliances, every selection made against a written allowance log so the budget holds before we break ground.
- 05 / 07
Relax while we build
We build it, weekly progress reports. Sit back and watch your home come to life, organized and on track.
- 06 / 07
Final walkthrough + handover
Punch list close, final inspection, owner walk-through. Every detail signed off before the keys change hands.
- 07 / 07
Long-term partnership
Avorino works with you before and after move-in. Our approach is relationship-first, not transaction-based.
The record
Licensed in California. Reviewed by Orange County homeowners.
- YearsOrange County experience
- 7+
- LicenseCalifornia General-B
- B-#1107538
- OC Cities + CommunitiesCoverage across all of Orange County
- 37
- RatingYelp
- 4.8★
- BBB ratingAccredited Business
- A+
As featured in
Detached ADU (Ground Up) · Santa Ana
“Avorino built us an ADU recently. They provided the full design and rendering, pulled permits, and built our 1,000 sqft ADU from start to finish. Easy to work with, prices very competitive. We've already recommended Avorino to friends.”
ADU reviews
More ADU homeowners, in their own words.
“These are the best people in the business. I used Avorino to build my own ADU. They beat every single price I got and on top of that did an excellent job finishing it in no time. Truly the best of the best — highly recommended.”
“My parents are getting older and I wanted them close by, so I reached out to several contractors. Avorino really impressed me — extremely professional, timely, and clear communication throughout. The crew was respectful and made me feel comfortable. My parents were so happy with how their space turned out.”
“Avorino converted our RV garage to a custom ADU. Organized, clear communication, and easy to work with. Our architect made mistakes on the plans, but Avorino helped work through every issue. I highly recommend them.”
“They converted our one-car garage into a Junior ADU. The city was difficult to work with, and Avorino took care of everything with them. Whenever things came up, they were quick to respond. Six months after finishing, there are no issues at all. Their cost was very competitive — extra stars for being very professional. I'd definitely work with them again.”
Everything under one roof
One team. Design, permits, and the build.
No architect to hire, no city to chase. From first drawing to final walk-through, one point of accountability: Avorino.
No pressure. No surprises. Your number is free. So is changing your mind.
Start with your instant estimate →- Custom architectural plans + structural engineering
- Title 24 energy calculations, handled in-house
- City submittals + plan-check corrections, managed by Avorino
- One in-house team, weekly progress updates
- Tiered warranty: 1-yr fit & finish, 4-yr systems, 10-yr structural
- A free written, fixed-price quote that is yours to keep
- No obligation, no call center, no sales pressure
- Financing available, and you can pay it back from the rental income. See options →
Good questions
ADU questions, answered straight.
How much does an ADU cost in Orange County?
Most detached ADUs run about $245K–$440K+ depending on size, finish level, and your lot. The instant estimate above gives your ballpark in ~30 seconds; we confirm the exact figure with a free written quote.
How long does it take?
Most detached and attached ADUs take about 5–8+ months from contract to handover, with design and city permits included. Junior ADUs and garage conversions are typically 4–6+ months. We manage every step in-house so you’re never waiting on the city alone.
Do you handle the permits?
Yes. Fully in-house: architectural plans, structural engineering, Title 24, city submittals, and plan-check corrections. You sign once; we carry it all.
Will my lot qualify for an ADU?
Most Orange County lots can take some form of ADU. On the call we check setbacks, easements, and your city’s overlays and tell you straight what your lot can carry.
Is financing available?
Yes, many homeowners finance their ADU and pay it back from the rental income. See your options on our financing page.
Is the instant estimate binding?
No. It’s an honest ballpark range, not a contract. We confirm your real number with a free written, fixed-price quote for your actual site.
Your ADU number is 30 seconds away.
Free instant estimate, a written quote texted to you, and a call only if you want one.