A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Mentone, CA
Adding an ADU to a Mentone property usually costs between $150,000 and $350,000 depending on size, site prep, and whether you go prefab or site-built. That’s the honest range before anyone walks your lot. Mentone sits on flat, sandy ground between Redlands and Yucaipa, tucked against the San Bernardino foothills, which means most ADU sites here need less slope work than homes up in the hills but still call for a close look at drainage and sun exposure. If you’re weighing an ADU, a home addition, or a room addition, call Benson ADU Builders at (903) 568-7222 and we’ll put a written price in your hands before any shovels turn.
Why Mentone Homes Are Different
Mentone’s housing stock is a mix of 1960s and 1970s ranch-style homes on generous lots, many of them zoned R-1 with room for a detached ADU in the back. That lot room is the biggest difference from a city like Redlands, where older historic districts squeeze setbacks tight. Here, a backyard ADU is often a realistic yes. But the lots aren’t all level and the soil is fast-draining sand and decomposed granite once you get east of the wash near Crafton Avenue, so we typically budget for compacted base work under any foundation. Heat matters too: Mentone summers run hot and dry, which pushes us toward insulated wall panels and heat-reflecting cladding, and it makes a properly sized mini-split a non-negotiable, not an upsell. Homes along Mentone Boulevard and up toward Greenspot Road tend to sit on deeper parcels, and we’ve seen several owners there go with a prefab ADU from Abodu or Cover specifically because the factory-built panel system shrinks the amount of time their yard is a construction site.
Our Main Mentone Services
Most Mentone calls to us start as one of two questions: can I add a rental ADU to this lot, or can I add square footage to this house without moving? Both answers live on their own pages, detailed below.
ADU Builders in Mentone
A detached backyard ADU in Mentone usually pencils out best on the deeper lots south of the 38 and along Greenspot Road, where a 600 to 1,000 square foot unit can fit without eating the whole yard. We walk the site, check setbacks (the legal distance from your property line), confirm utility tie-in points, and then put a written price in front of you for either a prefab unit from brands like Dvele or a site-built plan. Permits go through San Bernardino County for most Mentone parcels, and the review clock doesn’t change our promise of a written price first. Full details are on the ADU Builders in Mentone page.
Home Addition Contractor in Mentone
Adding onto a Mentone ranch-style home most often means extending out the back or converting a covered patio into conditioned space, and the big local variable is how the existing slab ties into the new foundation. Sandy soil drains well but shifts with heavy rain, so we plan the connecting footing accordingly. We coordinate the structural engineering, the permits, and the trades, and you get a fixed, written price before the first wall goes up. The full breakdown of what a home addition costs in Mentone and how we phase the work is on the Home Addition Contractor in Mentone page.
Room Addition Contractor in Mentone
A single room addition in Mentone, like a primary suite or a home office off the back of the house, runs a tighter footprint than a full addition but still needs the same county permits and the same foundation care in this sandy soil. We typically frame and weatherproof the entire shell before tying into the existing roofline, which keeps your living space sealed during the build. You’ll know the total cost in writing before we start. See the Room Addition Contractor in Mentone page for room-by-room pricing and a typical Mentone timeline.
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 Mentone
We build with factory-engineered systems from James Hardie, Abodu, Cover, and Dvele, so Mentone homeowners can research quality before they commit. Panels and materials stage at our Inland Empire supply hub and arrive to your Mentone site on schedule. See our brands for the full list and what each one does best.
Pricing for ADU Company in Mentone, CA
| Service | Typical range in Mentone |
|---|---|
| Detached ADU (prefab, 600 – 750 sq ft) | $150,000 – $210,000 |
| Detached ADU (site-built, 600 – 750 sq ft) | $180,000 – $260,000 |
| Detached ADU (prefab, 900 – 1,200 sq ft) | $220,000 – $310,000 |
| Detached ADU (site-built, 900 – 1,200 sq ft) | $270,000 – $350,000 |
| Attached ADU (conversion of existing space) | $110,000 – $180,000 |
| Garage conversion to ADU | $120,000 – $190,000 |
| JADU (within existing home footprint) | $70,000 – $130,000 |
| Home addition, 300 – 600 sq ft | $120,000 – $210,000 |
| Home addition, 700 – 1,000 sq ft | $210,000 – $330,000 |
| Room addition, single space (200 – 350 sq ft) | $80,000 – $150,000 |
What pushes Mentone prices toward the top of those ranges is usually soil work, a dated panel that needs a service upgrade, or a long utility run from the street. Every quote we give is a written, fixed price before work starts, so the number you approve is the number you pay.
Neighborhoods We Serve in Mentone
We cover all of Mentone and the surrounding San Bernardino County pockets. Most of our Mentone projects are on the flatter residential streets east and west of Mentone Boulevard, with a regular flow of work up toward Greenspot Road and down along Mill Creek Road.
- Mentone Boulevard corridor
- Greenspot Road area
- Mill Creek Road area
- Lugonia Avenue area
- Crafton Hills foothills
Service Area – Cities Near Mentone
Benson ADU Builders serves Mentone and the surrounding area, with crews dispatched locally from our Inland Empire office. If you’re comparing contractors in nearby cities, we also work across Redlands, CA, Yucaipa, CA, Highland, CA, and Calimesa, CA, with the same written-price guarantee on every job.
Serving Mentone, CA - Our Local Coverage Area
We’re based in the Mentone 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 Mentone
Once you approve the written price and we pull permits, site work in Mentone typically starts within two to six weeks depending on county plan-check volume. Prefab ADUs from Abodu or Cover usually reach the foundation stage sooner because the module is built off-site while we grade your lot. Call (903) 568-7222 and we’ll give you a realistic start window for your specific property.
Most Mentone parcels fall under San Bernardino County jurisdiction, which means county building permits, setback checks, and utility tie-in approvals. We handle the full permit package for you, and the written price we give you includes all county fees, so there’s no surprise line item later.
Yes. Mentone lots vary in shape and several sit near sandy washes, so we start every project with a site walk that checks grade, drainage, and access for concrete trucks and panel delivery. If your lot needs extra base work or a retaining element, that cost goes into your written estimate before you sign anything. Call (903) 568-7222 for a free site walk and estimate.
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 Mentone Customers Say
"Booked a consult online and met the project manager two days later. Weekly progress updates arrived by text with photos. ADU finished on schedule."
- Hannah W."Clean, quiet crew. They respected the neighbors, kept noise to working hours, and swept the driveway every evening."
- Hope C."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N.
