Orange County ADUs
What will your ADU cost?
Most Orange County ADUs run $245K–$440K+. Tell us about your project and Avorino sends you a free, written, fixed-price estimate — design, permits, and build, all under one roof.
- A free, written, fixed-price estimate
- Design, permits & build — all under one roof
- Financing available — many homeowners offset it with rental income
- No call center, no sales pressure
B-#11075387+ yrs37OC cities & communities
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.”
Which ADU fits your vision?
What an ADU typically costs in Orange County.
Use this to narrow your options. Then we’ll walk you through which type your lot can take — setbacks, soils, and the overlays your city adds.
Standalone unit on your property. Most rental upside, longest schedule, biggest ROI when the property has the room.
- Best for
- Properties with side or rear setback room for a free-standing unit.
- Typical size
- 500 – 1,200 sqft
- Bedrooms
- Studio – 3 BR
- Includes
- New foundation, full kitchen + bath, independent utilities.
These are typical Orange County ranges — we confirm your number against setbacks, soils, and your city’s overlays.
Avorino builds across Orange County.
Why Avorino
Why homeowners choose Avorino.
An accessory dwelling unit is a self-contained home on your existing lot — detached, attached, or a conversion. We help you from step one: site check, design, permits, and the build, all in-house.
- We bring your vision to reality — from first drawings to final inspection
- We handle city submittals and plan-check corrections in-house
- We send weekly progress updates during construction
- We’ve built ADUs across 37 Orange County cities
I am so happy I used Avorino to build my two custom homes in Santa Ana. The team was absolutely amazing and made the whole process seamless and streamlined. The quality of work was absolutely fantastic and top notch all the way. Avorino treated my project as if it was their own and I knew I was in good hands — 10/10 experience.
Process
Five steps to a permitted ADU.
We handle every step in-house, from design to the build.
- 01
Free consultation
Setbacks, easements, utility lines, neighbor friction reviewed together. We tell you what your vision can carry before drawings.
- 02
Drawings
We turn your vision into a buildable blueprint — architectural set, structural engineering, soils when needed.
- 03
City permits
We take care of the submission, comments, and resubmittal to the city. You sign once; we carry it all.
- 04
Construction
Foundation, framing, mechanical, electrical, and plumbing, finishes. Weekly progress reports throughout.
- 05
Walk + warranty
Final inspection, owner walk-through, then the tiered warranty (1-year fit & finish, 4-year systems, 10-year structural).
AI tools that help you bring your vision to reality.
Calibrated against active Avorino OC builds — not stock estimates. Run them anonymously; the results are yours to keep or share with us.
ADU Cost Calculator
Instant cost-range read on your ADU — calibrated to your city, square footage, finish level, and ADU type.
Run the toolADU ROI Calculator
Project rental income, payback period, and long-term return on your ADU — modeled on real Orange County rents.
Run the toolGrab the free ADU cheat sheet.
Costs, timelines, and what your city allows — the 5-page guide homeowners actually use. Your quote form is one scroll up.
- 7+YearsOrange County experience
- B-#1107538LicenseCalifornia General-B
- 37OC Cities + CommunitiesCoverage across all of Orange County
- 4.8★RatingYelp