A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Corona, CA
Adding an ADU or home addition in Corona means working with a city that has made accessory units a real priority, and with homes that bring their own quirks: sprawling stucco ranches from the 60s through 90s, HOA design rules in planned communities, and summer heat that pushes every HVAC and insulation decision. Sutton ADU Builders handles all three of the main Corona jobs, detached ADUs, whole-home additions, and room additions, each with a written price before work starts. If you’re trying to figure out whether your Corona lot can support an ADU, call (831) 217-6083 and we’ll walk you through what’s realistic.
Why Corona Homes Are Different
Corona’s housing stock is dominated by single-family homes built from the 1960s to the 1990s, many of them two-story stucco with generous lot sizes that look ideal for a detached ADU, until you check the electrical panel. Homes in the older central part of Corona, near the 91 freeway, frequently run on undersized 100-amp panels, and an ADU with a full kitchen and laundry will almost always require an upgrade to 200 amps before anything else moves. That’s a cost and a timeline item you want to know about on day one, not after demo starts.
The other big variable is the HOA. Planned communities like Corona Hills and South Corona often write their CC&Rs to require that any ADU match the primary home’s exterior, stucco finish, roofline, window trim. That’s a design constraint a pre-approved plan won’t solve. And then there’s the climate itself: summers over 100°F mean the cooling load drives the HVAC spec, and Santa Ana winds make window and roof flashing details a place where shortcuts show up as dust on the windowsill and whistling at the sill plate. Mild winters do allow year-round construction here, which helps scheduling.
Our Main Corona Services
Corona homeowners call us about two things most often: adding square footage to the existing home, and building a separate ADU in the yard. Both are covered below, each with its own dedicated Corona page.
Home Addition Contractor in Corona
A home addition in Corona typically means tying new square footage into a 60s-to-90s stucco structure, which means matching rooflines and stucco texture so the addition doesn’t look bolted on. Many of these projects run into the same 200-amp panel question as ADUs, especially when the addition includes a kitchen or laundry. We quote the entire job including the panel, not just the framing. Home Addition Contractor in Corona
ADU Builders in Corona
Corona’s pre-approved ADU plan program is a genuine advantage here, it’s one of the fastest permitting paths in Riverside County, but the pre-approved plans are capped at detached units under 800 square feet. If you want a larger detached unit or a garage conversion with a custom floor plan, you’re back to full design review, and that’s where a builder who knows Corona’s plan check process saves months. ADU Builders in Corona
Room Addition Contractor in Corona
A room addition, one bedroom, a home office, a larger family room, has a lighter permit touch than a full addition, but Corona’s summer heat still drives the HVAC and glazing choices. Older stucco homes in Corona were built for a different climate expectation, so a southwest-facing room addition needs real attention to window spec and insulation. Room Addition Contractor in Corona
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Corona
We work with prefab and modular ADU lines including Cover, Dvele, and Mighty Buildings, and we stock common replacement parts and trim hardware locally for faster turnaround on warranty follow-ups. Visit our brands page to see the full list and what each system is best suited for.
Pricing for ADU Company in Corona, CA
Here’s what we typically see in Corona, before site work, utility upgrades, or HOA-required design changes are factored in. These are real ranges from real Corona projects, not statewide averages.
| Service | Typical range in Corona |
|---|---|
| Detached ADU, 400 – 800 sq ft (pre-approved plan path) | $180,000 – $320,000 |
| Detached ADU, 800 – 1,200 sq ft (custom design) | $320,000 – $480,000 |
| Garage conversion to ADU | $110,000 – $190,000 |
| Room addition, 200 – 400 sq ft | $90,000 – $160,000 |
| Home addition, 400 – 800 sq ft | $160,000 – $340,000 |
| Electrical panel upgrade to 200 amps | $3,500 – $7,000 |
| Foundation and site work (detached ADU) | $25,000 – $60,000 |
| HOA-required exterior matching (stucco, roof, trim) | $8,000 – $25,000 |
The two things that push prices up fastest in Corona are electrical panel capacity and HOA exterior-matching requirements, both of which are knowable before you sign a contract. That’s exactly why Sutton writes the full price before any work starts, no exceptions, and the number on that page is the number you pay unless you change the scope yourself.
Neighborhoods We Serve in Corona
Sutton ADU Builders works across the whole city, from the established planned communities to the older central neighborhoods. Most Corona appointments can be scheduled within the week.
- Corona Hills
- South Corona
- Central Corona (near the 91)
- Eagle Glen
- Sierra del Oro
Service Area – Cities Near Corona
If your project sits just outside the Corona city line, we also serve Norco, CA, Riverside, CA, Rancho Cucamonga, CA, and Claremont, CA. Each city has its own permit desk and plan check culture, and we quote accordingly.
Serving Corona, CA - Our Local Coverage Area
We’re based in the Corona area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Company in Corona
If your detached ADU is under 800 square feet and you use one of Corona’s pre-approved plans, permitting can move in weeks rather than months. Custom designs, garage conversions, and anything that needs HOA approval add time to the front end. Call (831) 217-6083 for a realistic timeline on your specific lot.
California state law limits an HOA’s ability to prohibit ADUs outright, but Corona HOAs in planned communities often impose design standards, exterior matching, roofline, paint, trim, that add cost and review time. We read the CC&Rs with you before design starts, not after.
If your home is in central Corona near the 91 and still has a 100-amp panel, a 200-amp upgrade is almost always required once the ADU gets a full kitchen and laundry. On newer Corona homes with 200-amp service already in place, it may not be needed at all. The electrical assessment is part of every written quote.
To get a written price for your Corona ADU, room addition, or home addition project, call (831) 217-6083. Sutton ADU Builders sends a real person to your door, photo-badged, background-checked, with a written number before a single tool is lifted.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Corona Customers Say
"Itemized estimate with allowances laid out. Final cost was within a hair of the quote."
- Naomi R."Detached unit with a small kitchen and bath. Windows and finishes were nicer than I expected for the budget."
- Philip S."Great build and clear weekly updates. Plumbing inspection got pushed a week because of the city, which wasn't their fault, but it set us back a bit."
- Lucia P.
