ADU & Room Addtion Construction in Orange County
——— ADU & ROOM ADDITIONS · ORANGE COUNTY
Expand Your Home. Grow Your Investment.
Custom kitchen remodeling in Orange County — designed around your lifestyle, built to last a lifetime.
LICENSED & INSURED 20+ YEARS OC SPECIALISTS A-Z SERVICE
20+
YEARS OF EXCELLENCE
A-Z
DESIGN & BUILD
100%
LICENSED & INSURED
5.0
GOOGLE RATING
WHAT WE BUILD ———
More Space. More Value.
More Possibility
Whether you need a detached ADU for rental income, a guest suite for family, or a room addition that flows seamlessly with your existing home — RIA Group designs and builds it all under one roof. We handle design, engineering, permits, and construction so you don't have to coordinate a thing.
-
Custom floor plans, interior design, and material selections — all tailored to your property and local zoning requirements
-
We handle every ADU permit, SB 9 application, and city inspection in Orange County — you never deal with a permit office.
-
Plumbing, electrical, HVAC, and separate utility connections — all compliant with California building codes.
-
Room additions are designed to match your existing home's architecture, materials, and aesthetic — inside and out.
-
Flooring, cabinetry, countertops, fixtures, and lighting — finished to the same luxury standard as the rest of your home.
-
![Minimalist bedroom with white bedding, wood bench, warm pendant lighting, and large window with natural light]()
Newport Beach Project
-
![Open living space with kitchenette, sliding glass door to patio spa, modern shelving, and light tile flooring]()
Newport Beach Project
-
![Modern bedroom with mirrored closet doors, hardwood floors, small workspace desk, and minimalist decor]()
Newport Beach Project
OC ADU RULES ———
What You Need to Know About ADUs in OC
California has made it easier than ever to build an ADU — but local Orange County rules still apply. RIA Group knows every city's specific requirements and handles every approval on your behalf.
1,200
Max Square Footage
Most California ADUs can be up to 1,200 sq ft. Junior ADUs (JADUs) max out at 500 sq ft.
California ADU Law
State law requires cities to approve compliant ADU applications — removing many previous barriers to construction.
SB 9
Parking Requirments
In most cases, ADUs in California do not require additional parking spaces — especially near transit.
0
Day Permit Timeline
Cities must approve or deny an ADU permit application within 60 days — and we track every deadline for you.
60
RIA Group Handles Everything
Navigating ADU permits in Orange County involves city planning, building departments, utility companies, and in some cases HOA approvals. RIA Group manages every single step — from your initial feasibility review through final certificate of occupancy. You don't make a single phone call to a government office.
OUR PROCESS ———
From Idea to Move-In Ready — We Manage It All
01
Free Consultation
We assess your property, review zoning, and determine what's possible before anything else.
02
Design
Custom floor plans and material selections tailored to your lot, home, and vision.
03
Estimate
Fully itemized written estimate — every cost line by line, no surprises or hidden fees.
04
Permits
We handle all ADU permits, city submissions, HOA approvals, and utility connections.
05
Build
Licensed crew, daily oversight, and weekly client updates from foundation to finish.
06
Move-In Ready
Final inspection, certificate of occupancy, and complete walkthrough — ready to rent or occupy.
GET STARTED ————
Get your Free
ADU or Addition Estimate
Tell us about your project and we'll follow up within 24 hours to schedule your free in-home consultation. No pressure, no obligation — just an honest conversation about your vision.
Response within 24 hours
Free in-home consultation
Fully itemized written estimate
Zero obligation or pressure
CA Licensed #1143899
WHY RIA GROUP ——-
Why Homeowners Choose RIA Group for Their ADU or Addition
OC ADU Permit Experts
We know every city's specific ADU rules across all 34 Orange County municipalities — saving you time and preventing costly mistakes.
Full Design & Build Under One Roof
Architecture, engineering, permits, and construction — one team, one manager, zero handoffs
Architecturally Seamless Results
Every addition is designed to match your existing home's style, materials, and character — inside and out.
Transparent Pricing Always
Fully itemized estimates with zero hidden costs — what we quote is what you pay from day one.
WHERE WE BUILD ———
Kitchen Remodeling Across Orange County
RIA Group proudly serves all 34 cities in Orange County. We know the local permit offices, preferred suppliers, and neighborhoods — so your project runs smoother from day one.
Newport Beach
Laguna Beach
Mission Viejo
Aliso Viejo
San Clemente
Yorba Linda
Anaheim Hills
Brea
Every city in Orange County has slightly different ADU rules. Setback requirements, height limits, and owner-occupancy rules vary by municipality. RIA Group knows every local code — and handles every approval for you. Don't see your city? Contact us — we serve all of OC.