A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Orange, CA
Fielding ADU Builders is the ADU and room-addition contractor serving Orange, CA under The Garrison Standard: a written price before any work starts, a written one-year guarantee on every project, and a crew that arrives background-checked and in uniform. Orange is a city of older single-story homes on generous lots, and that combination creates real opportunity for ADUs, garage conversions, and additions. If you’re planning one of those projects, call (361) 315-4177 and we’ll walk you through what it will cost before you commit to anything.
Why Orange Homes Are Different
Orange’s housing stock leans heavily toward mid-century single-story homes, many built between the 1940s and 1970s. That matters for ADU work. A 1960s slab foundation in the neighborhoods around Old Towne behaves differently than a newer post-tension slab, and we check for that before we quote. The city’s historic district overlay around the Plaza adds another layer: if your property falls inside it, our ADU or garage conversion plans have to clear design review, which can add weeks to permitting. We would rather tell you that on the first call than have you find out at the counter.
The terrain here is mostly flat, which keeps site prep simpler than the hillside work you see in other parts of the county, but Orange gets real heat in the summer. That means insulation selection matters more than people think, especially for a detached ADU that sits in direct sun. We also deal with the city’s setback rules, which are standard for older Orange County lots but still trip people up when a garage sits close to the property line. A setback variance (the city’s written permission to build closer to the property line than the standard rule allows) is sometimes the difference between a project that works and one that does not.
Our Main Orange Services
Orange homeowners most often call us for three things: adding a room, converting a garage, and building a detached ADU. Each one has its own page with pricing and details specific to this city.
Room Addition Contractor in Orange
A room addition in Orange typically means extending a single-story home outward, often into a backyard that already has the space for it. The work involves tying a new foundation into the existing slab, matching rooflines, and pulling permits through the city’s building department. Orange’s older homes sometimes need electrical panel upgrades as part of the job, which we factor into the written quote before work starts. Room Addition Contractor in Orange
Garage Conversion Contractor in Orange
Garage conversions work well in Orange because so many homes here have attached two-car garages that sit mostly unused. The job means turning that square footage into living space: insulation, drywall, flooring, and a permit that reclassifies the space. Earthquake retrofitting and tie-down requirements are part of the conversation on older Orange garages, and we handle those details as part of the permit package. Garage Conversion Contractor in Orange
ADU Builders in Orange
A detached ADU in an Orange backyard is a bigger project, but the city’s lot sizes often make it possible. We build conventional stick-frame ADUs and we also work directly with prefab platforms like Cover and Dvele, which can shorten the on-site timeline significantly. The right choice depends on your lot, your budget, and how the structure will sit relative to existing utilities. ADU Builders in Orange
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 Orange
We work with several prefab and modular ADU platforms homeowners in Orange frequently ask about, including Cover, Dvele, and Mighty Buildings. Parts and finishes for these systems are available through our supplier network, and turnaround on sourcing is typically days, not weeks. See our brands for the full list.
Pricing for ADU Company in Orange, CA
These figures reflect what we typically see on Orange projects. Permit fees, design review, and utility connections are separate and quoted before any work starts.
| Service | Typical range in Orange |
|---|---|
| Detached ADU (stick-frame, 400 – 600 sq ft) | $180,000 – $260,000 |
| Detached ADU (prefab/modular, e.g. Cover or Dvele) | $150,000 – $240,000 |
| Garage conversion (attached, 400 sq ft) | $80,000 – $120,000 |
| Garage conversion with bathroom addition | $100,000 – $140,000 |
| Room addition (300 – 400 sq ft) | $90,000 – $150,000 |
| Room addition with en-suite bathroom | $130,000 – $200,000 |
| Electrical panel upgrade (if required) | $3,500 – $6,000 |
| Foundation repair or reinforcement (older slab) | $8,000 – $25,000 |
| Design and permitting package | $12,000 – $22,000 |
What pushes a price up in Orange is usually the condition of the existing structure: a 1950s slab that needs reinforcement, an electrical panel that will not pass current code, or a historic-district property that needs design review. Whatever the number is, we put it in writing before any work begins, and that is the number on the final invoice.
Neighborhoods We Serve in Orange
We work across Orange, including the historic core and the newer subdivisions to the east. Each area has its own permit quirks, but scheduling is consistent: most estimates happen within a week of your call.
- Old Towne Orange (historic district, design review may apply)
- Orange Park Acres (larger lots, more room for detached ADUs)
- El Modena (mid-century homes, common panel upgrade needs)
- Mabury Park (post-war tract homes, attached garages)
- Serrano Heights (newer construction, different foundation types)
Service Area – Cities Near Orange
Fielding ADU Builders serves Orange and the surrounding cities. If you are just outside the city line, we can still help. We regularly work in Santa Ana, CA, Tustin, CA, Garden Grove, CA, and Placentia, CA. Call us and we will confirm coverage for your address.
Serving Orange, CA - Our Local Coverage Area
We’re based in the Orange 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 Orange
Most Orange homeowners get an estimate visit scheduled within a week of calling. The visit takes about an hour, and the written price follows within a few days. Call (361) 315-4177 to get on the schedule.
Standard ADU permits in Orange move at a typical Orange County pace, though properties in the Old Towne historic district face an additional design review step. We handle that paperwork as part of the permit package and keep you informed on timelines.
Yes. HOA review runs parallel to city permitting, and we provide the plans and documentation your HOA will ask for. The city’s ADU rules generally override HOA restrictions, but we coordinate both tracks so nothing stalls. Call (361) 315-4177 for a free estimate and we will map out the full process for your property.
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 Orange Customers Say
"Built a detached ADU behind our house. The builder is a veteran and runs the site like a platoon: schedule posted, crew on time, everything labeled. Finished within a few days of the date."
- Ken W."Room addition over the back patio. Framing is square, windows are tight, and the roofline matches."
- Danny L."Foundation and slab poured on schedule. Crew kept the yard orderly."
- Marian J.
