A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Orange County, CA
Fielding ADU Orange County builds permitted ADUs, garage conversions, and room additions across Orange County. The work here runs into a patchwork of city codes: 34 municipalities, each with its own setback, parking, and owner-occupancy rules layered on top of state ADU mandates. That’s the single biggest reason Orange County homeowners call us. They’ve discovered that an ADU approved in Santa Ana can hit a wall in Irvine, and they want a builder who knows the difference before the plans go in. Call (424) 577-4306 for a written, line-item price on your project.
Why Orange County Homes Are Different
Orange County’s housing stock is mostly post-1960s single-family tract homes on lots wide enough to hold a detached ADU without crowding the main house. Many properties in older cities like Garden Grove and Santa Ana have alley-loaded lots and detached garages set back from the street, which opens up a very specific opportunity: a garage conversion or a second-story ADU built above the existing garage. In master-planned communities like Irvine, the lots are tighter, HOA covenants sometimes still restrict rentals, and design review adds a layer of approval that doesn’t exist in unincorporated pockets.
Climate works in the homeowner’s favor. The Mediterranean weather lets crews pour foundations and frame walls year-round, and the mild winters mean ADUs don’t need the heavy insulation packages common in colder states. But Orange County ADUs do need real attention to termite protection and seismic anchoring – two Southern California realities that get written into the structural plans, not left to chance. We build for both from day one.
Our Main Orange County Services
Most Orange County homeowners come to us for one of three projects: adding a room to the existing house, converting a garage into living space, or building a detached ADU in the backyard. Each has its own permitting path and its own page here.
Room Addition Contractor in Orange County
A room addition in Orange County usually means expanding the main home’s footprint, often off the back or into a wide side yard that tract-home layouts left unused. Coastal cities like Newport Beach enforce stricter design review than inland cities, so the plans and materials have to be right the first time. We handle the structural work, the permits, and the finish trim, and we put the full price in writing before any lumber shows up. See the full breakdown on our Room Addition Contractor in Orange County page.
Garage Conversion Contractor in Orange County
Garage conversions are the fastest path to rentable or in-law space in Orange County because the shell, foundation, and roof already exist. The catch is the city-specific detail: some Orange County cities require the converted garage to match the main house’s elevation, others want a carport or replacement parking, and a few still tie approval to owner-occupancy. We walk the permit path for you. Details are on the Garage Conversion Contractor in Orange County page.
ADU Builders in Orange County
Detached and attached ADUs are where Orange County’s lot stock shines. The wide side yards and rear setbacks common in tract neighborhoods give us room for a 500 to 1,200 square foot unit without touching the main house. We build conventional, prefab, and modular ADUs, and we know which cities in Orange County move permits quickly and which ones need a variance. Read the full scope on the ADU Builders in Orange County page.
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 County
We install and finish ADUs from Abodu, Cover, and Mighty Buildings, and we frame conventional builds with James Hardie siding where the design calls for it. Parts and panels for these systems are available through local Orange County suppliers, which keeps lead times short. See our brands for the full list and what each system does best.
Pricing for ADU Company in Orange County, CA
| Service | Typical range in Orange County |
|---|---|
| Garage conversion (finished) | $85,000 – $140,000 |
| Detached ADU (conventional build, 500 – 800 sq ft) | $180,000 – $290,000 |
| Detached ADU (prefab or modular, 400 – 700 sq ft) | $150,000 – $260,000 |
| Attached ADU (junior or full, 400 – 700 sq ft) | $140,000 – $240,000 |
| Room addition (ground level, 300 – 500 sq ft) | $120,000 – $210,000 |
| Second-story ADU above existing garage | $200,000 – $320,000 |
| Site work, foundation, and utility trenching | $18,000 – $42,000 |
| Plans, engineering, and permit fees (city-dependent) | $8,000 – $25,000 |
What pushes the number up in Orange County is almost always site-specific: poor soil, a steep lot, a required setback variance, or a city design review that demands upgraded materials. We hand you the written price before any work starts, and that number does not move unless you change the scope.
Neighborhoods We Serve in Orange County
We run ADU and addition projects throughout Orange County, from the older grid neighborhoods to the newer master-planned tracts. Typical response time for a site visit in Orange County is two to four business days.
- Anaheim Hills
- Westminster
- Lake Forest
- San Clemente
- Tustin
Service Area – Cities Near Orange County
Fielding ADU Orange County works directly with homeowners in Santa Ana, CA, Orange, CA, Newport Beach, CA, and Fountain Valley, CA. Scheduling and dispatch are coordinated through our Los Angeles office, and crews are staged locally so we’re never more than a short drive from your Orange County site.
Serving Orange County, CA - Our Local Coverage Area
We’re based in the Orange County 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 County
It depends on the city. In Orange County, some cities issue over-the-counter ADU permits in a few weeks, while others take three to six months with design review. We’ll tell you the realistic timeline for your specific city before you sign anything. Call (424) 577-4306 and ask us directly.
Yes, in some Orange County communities, particularly newer ones in Irvine and parts of south county. State law limits what HOAs can prohibit, but they can still impose design standards. We’ll review your HOA’s rules early so the plans don’t get rejected at the board level.
We cover the full county, from Seal Beach south to San Clemente and inland to Yorba Linda and Rancho Santa Margarita. If your Orange County property has a usable side yard, rear setback, or existing garage, we can assess it. Estimates are free.
If you’re ready for a real number on your Orange County ADU, garage conversion, or room addition, call (424) 577-4306. You’ll get a live person, a free site visit, and a written price before any work begins.
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 County Customers Say
"Foundation and slab poured on schedule. Crew kept the yard orderly."
- Marian J."Clear price breakdown. Change orders were all in writing."
- Hal P."Insulation, drywall, and finishes were all well done. Feels like part of the house."
- Pete O.
