ADU · Brea
Garage Conversion ADU, Brea
A Brea garage conversion ADU: an under-used two-car garage turned into a bright, open-plan studio-style unit with a full kitchen — the fastest, most budget-friendly path to a legal rental unit in Orange County.
Project record
400
sq ft
approx.
- City
- Brea, CA
- Builder
- Avorino · Lic. #1107538
- Typical budget
- $85K–$170K+ (garage conversion)
- Typical timeline
- 4–6+ months build, after design + permits
- Warranty
- 1-yr fit & finish · 4-yr systems · 10-yr structural
- Layout
- approx. Studio · 1 bath
- Stories
- Single-story
- Build
- Conversion
Sizes and room counts marked approx. are estimates from plans and photos.
Scope of work
What this build involved.
- Two-car garage converted to a legal ADU
- Full kitchen with island seating + open living
- Insulation, drywall, and egress brought to habitable code
- Electrical panel work + dedicated circuits
- Exterior door + window package for light and egress
Permits & process
Garage conversions skip foundation and framing review, so Brea's plan check runs lean — the work is proving habitability: insulation, egress, ventilation, and electrical capacity. State ADU law protects the conversion right even where HOAs object.
The build
Conversions are the value play: the shell exists, so budget goes into what you touch daily — kitchen, bath, light, and sound insulation from the main house.
Plates
Finish + structural detail.
15 finished frames
During construction
From garage to ADU.
During construction — from our Instagram story
The original garage before conversion, exposed rafters and old shelving Rebar over the vapor barrier inside the stripped garage shell The new slab being poured Garage opening stripped to studs with new sheathing Bathroom partition framing with drain and supply rough-ins Insulation in and the first drywall sheets up Shower tile set before grout, black-trim niche White shaker cabinets installed, protection tape still on
What clients say about this kind of build
“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. Six months after finishing, there are no issues at all. Their cost was very competitive.”
Next step
Want a written estimate for your Brea project?
We review your project personally and follow up as soon as possible. Same-week consultation, written timeline, calibrated to Brea’s permit reality.