A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Riverside, CA
Fielding ADU Builders is the ADU and room-addition specialist serving Riverside, CA from our Inland Empire office. We’re part of the Garrison Partners family, and we build detached ADUs, garage conversions, and room additions under one written contract with one clear price handed to you before work starts. Riverside’s mix of 1920s bungalows, 1950s tract homes, and newer hillside construction means no two lots are the same, so we plan each job around your specific setback, soil, and access conditions. Call (361) 315-4177 and a live person answers, any hour.
Why Riverside Homes Are Different
Riverside’s housing stock runs from prewar craftsman bungalows near downtown to mid-century single-story tracts in the Arlington and La Sierra areas, with newer construction pushing up into the hills around Alessandro Heights and Canyon Crest. That spread matters for ADU and addition work. Older homes often have undersized electrical panels and cast-iron sewer lines, which means more upgrade work before framing can start. Hillside lots in the Canyon Crest and Alessandro Heights areas frequently trigger grading reviews and setback variance requests, the city’s written permission to build closer to a property line than the standard rule allows.
The climate pushes the schedule too. Riverside summer heat regularly tops 100 degrees, so concrete pours and roof work get scheduled for early morning, and materials like adhesives and sealants need storage in shaded, ventilated areas before installation. The Santa Ana winds in fall mean framing crews brace walls and trusses on a tighter schedule than they would in coastal cities. We plan around all of this before the first inspection, because a missed weather window in Riverside means a week of delay, not a day.
Our Main Riverside Services
Riverside homeowners call Fielding ADU Builders most often for two things: adding living space onto an existing house, and converting a garage or building a new backyard unit. Each has its own Riverside page below.
Room Addition Contractor in Riverside
A Riverside room addition usually means extending a single-story home outward to add a bedroom, bathroom, or family room. The work involves foundation matching, roof tie-in, and matching stucco or siding texture so the addition doesn’t look bolted on. On Riverside’s many mid-century lots, one common issue is foundation settling, so we check the existing slab before we commit to a tie-in plan. We price the whole job in writing first, then pull permits and build to code. Full details are on our Room Addition Contractor in Riverside page.
Garage Conversion Contractor in Riverside
A garage conversion in Riverside turns an existing attached or detached garage into living space without changing the home’s footprint. That usually works best on Riverside’s older lots, where the garage may be undermultiplexed for modern cars but sized well for a one-bedroom unit. We handle slab leveling, wall insulation, electrical upgrade, and the drywall finish, and we pull the change-of-use permit so the conversion is legal under Riverside’s current building code. Details are on our Garage Conversion Contractor in Riverside page.
ADU Builders in Riverside
A detached backyard ADU in Riverside is often the cleanest path to a rental unit or family quarters, and most Riverside lots in the Arlington and La Sierra areas have enough rear-yard depth to fit one under the city’s ADU ordinance. We build both conventional stick-framed units and prefab units from Abodu, Dvele, and Mighty Buildings, depending on your lot access, budget, and timeline. We handle the setback review, foundation, utility connection, and final inspection. Full detail is on our ADU Builders in Riverside 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 Riverside
We work with Abodu, Cover, Dvele, and Mighty Buildings on prefab and panelized ADU platforms, and we frame conventional additions with James Hardie siding where the budget favors stick-built. When a Riverside homeowner has already researched a specific prefab brand, we can usually take the project from factory order to final inspection our brands page shows the platforms we build with.
Pricing for ADU Company in Riverside, CA
| Service | Typical range in Riverside |
|---|---|
| Garage conversion to studio ADU | $85,000 – $135,000 |
| Garage conversion to one-bedroom ADU | $110,000 – $165,000 |
| Detached backyard ADU (one-bedroom, conventional build) | $180,000 – $260,000 |
| Detached backyard ADU (two-bedroom, conventional build) | $220,000 – $320,000 |
| Prefab one-bedroom ADU (Abodu or Dvele, including site work) | $190,000 – $280,000 |
| Prefab two-bedroom ADU (Mighty Buildings or Cover, including site work) | $230,000 – $340,000 |
| Room addition (bedroom and bathroom, 300 – 500 sq ft) | $120,000 – $210,000 |
| Room addition (primary suite, 400 – 600 sq ft) | $150,000 – $250,000 |
| Electrical panel upgrade (if required for ADU or addition) | $3,500 – $6,500 |
| Foundation and grading work (hillside lots) | $15,000 – $45,000 |
What pushes a Riverside price up is usually the lot: hillside grading, retaining walls, and long utility runs to the ADU site all add cost. A flat Arlington lot with a short sewer tie-in will land at the lower end. Whatever the number is, we put it in writing before work starts, and that number is the number on the final invoice.
Neighborhoods We Serve in Riverside
Our crews work across Riverside, from the flat central tracts to the hillside subdivisions. We schedule projects in each area based on permit office hours and inspector availability, so most Riverside homes get a site visit within a few business days of the first call.
- Arlington
- La Sierra
- Canyon Crest
- Alessandro Heights
- Wood Streets
Service Area – Cities Near Riverside
From our Inland Empire office we also serve homeowners in nearby cities where the lot sizes and permit rules are similar to Riverside’s. If you’re just outside the city line, we can usually schedule a site visit the same week: Grand Terrace, CA, Bloomington, CA, Colton, CA, and Loma Linda, CA.
Serving Riverside, CA - Our Local Coverage Area
We’re based in the Riverside 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 Riverside
Most Riverside homeowners get a site visit within a few business days of the first call. We schedule around Riverside’s permit office hours and inspector availability, so call (361) 315-4177 and we’ll set a window that works.
We pull every city permit for your Riverside project and submit HOA applications where required. We price permits into the written quote, and we manage the city inspections from first check to final sign-off.
No. The price you approve in writing on day one is the number on the final invoice. Change orders happen only if you ask for different scope, and we price any change in writing before we do it.
Call (361) 315-4177 to schedule a free estimate with Fielding ADU Builders in Riverside, CA. A live person answers, any hour.
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 Riverside Customers Say
"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."Garage conversion with a new bath and kitchenette. Permit was handled by them. Inspection passed first time."
- Sheila B.
