A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in San Bernardino, CA
We’re Benson ADU Builders, and we handle ADU construction, home additions, and room additions across San Bernardino, CA. This page is your starting point. Our three main services each have their own dedicated San Bernardino page, linked just below, so you can go straight to the details you need. What makes San Bernardino jobs different comes down to three things: older housing stock that predates modern foundation and electrical standards, intense summer heat that punishes cheap materials, and a permit process that rewards contractors who show up with complete plans the first time. If you want to talk to a person about your project right now, call (903) 568-7222.
Why San Bernardino Homes Are Different
San Bernardino’s housing stock runs older than most of the Inland Empire. Many homes north of Highland Avenue and around Arrowhead were built between 1900 and 1960, which means we regularly work with pier-and-post foundations, asbestos-era siding, 60-amp electrical panels, and cast-iron waste lines. An ADU or addition on one of these lots is not a drop-in project. The foundation often needs selective reinforcement before framing starts, and the electrical service frequently needs an upgrade to carry a second dwelling unit.
The climate is the second factor. San Bernardino summers routinely hit triple digits, which pushes us toward high-R-value insulation, light-colored roofing, and window glazing that actually cuts solar gain. A cheap prefab panel can turn an ADU into an oven by 3 p.m. We spec materials accordingly. Terrain matters less in the flats around Del Rosa and University, but hillside lots up toward Verdemont and Devore often trigger geotech review for slope stability. That adds cost, and it is better to know that before you fall in love with a plan than after. Permit reality here: the city reviews for setbacks, lot coverage, and fire access, and a complete submittal moves measurably faster than a partial one. We prepare full drawing sets from day one.
Our Main San Bernardino Services
San Bernardino homeowners most often call us about two things: building a new ADU on an existing lot, or adding square footage to the home they already have. Here is what each one involves in San Bernardino specifically.
ADU Builders in San Bernardino
An ADU in San Bernardino is usually a detached backyard dwelling or a garage conversion, and the economics make sense fast when monthly rent for a one-bedroom runs where it does across the city. We help you decide between site-built and prefab, walk the setback rules on your specific lot, and handle the full permit package so your project does not stall in review. Every option gets a written price before any work starts. ADU Builders in San Bernardino covers the full process, including real cost ranges and what fits on a typical San Bernardino lot.
Home Addition Contractor in San Bernardino
A home addition means expanding the footprint of the house itself: a new primary suite, a bigger kitchen, a second living room. In San Bernardino, the older the home, the more we plan for what is inside the walls before we add outside them, especially electrical capacity and foundation condition. We use the same written-price discipline on a 400-square-foot bump-out as we do on a full ADU. Home Addition Contractor in San Bernardino has the specifics, including what additions cost per square foot here and which neighborhoods present the smoothest paths.
Room Addition Contractor in San Bernardino
A room addition is the lighter-touch version of the same idea: one new room built onto the existing structure, usually without moving kitchens or bathrooms. These jobs are popular in San Bernardino for home offices and bedrooms for growing families. We tie the new foundation into the old one correctly, match the roofline so it does not look bolted on, and keep the whole project on a fixed, written quote. Room Addition Contractor in San Bernardino explains the process and the price ranges for San Bernardino specifically.
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 San Bernardino
We are authorized to build with leading prefab and materials brands including Cover, Dvele, and Boxabl, which means San Bernardino homeowners get named, researchable product options instead of one take-it-or-leave-it design. See the full list on our brands page.
Pricing for ADU Company in San Bernardino, CA
| Service | Typical range in San Bernardino |
|---|---|
| ADU construction (prefab, 400 – 800 sq ft) | $180,000 – $320,000 |
| ADU construction (site-built, 400 – 800 sq ft) | $220,000 – $380,000 |
| Garage conversion to ADU | $140,000 – $240,000 |
| JADU (junior ADU, converted bedroom) | $80,000 – $140,000 |
| Detached ADU foundation (pier-and-post retrofit) | $18,000 – $35,000 |
| Electrical service upgrade (100A to 200A) | $4,500 – $9,000 |
| Home addition (mid-range, 300 – 600 sq ft) | $150,000 – $320,000 |
| Room addition (single room, 150 – 300 sq ft) | $75,000 – $160,000 |
Prices in San Bernardino push toward the high end when the home is on a hillside lot requiring geotech review, when the original foundation needs structural work, or when a service panel upgrade is required. You always get a written price before any work starts, and that price stays fixed through the job.
Neighborhoods We Serve in San Bernardino
Our crews work throughout San Bernardino, CA, from the flatter central streets up into the foothills. We know the lot sizes and permit patterns in the areas where ADUs and additions are most common.
- North Park
- Arrowhead
- Verdemont
- Del Rosa
- Downtown San Bernardino
Response time across the San Bernardino service area is typically one to two business days for an estimate visit, depending on schedule volume.
Service Area – Cities Near San Bernardino
Benson ADU Builders serves the broader Inland Empire from its Riverside-San Bernardino metro office. If you are in a neighboring city, we can often reach you just as quickly. Homeowners in Loma Linda, CA, Highland, CA, Rialto, CA, and Colton, CA can call the same number and get the same written-price promise.
Serving San Bernardino, CA - Our Local Coverage Area
We’re based in the San Bernardino 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 San Bernardino
We typically schedule estimate visits within one to two business days for San Bernardino homeowners, depending on current volume. The call itself is answered by a live person, day or night. Call (903) 568-7222 to lock in a time.
Yes. We prepare the full permit package, including architectural drawings and structural calculations, and we submit directly to the City of San Bernardino. If your property has an HOA, we coordinate the application package, but HOA response times are outside our control.
No. The price we quote in writing before work starts is the price you pay unless you change the scope. Our 365-Day Done Right Promise stays in effect for a full year after completion, and if anything we covered fails, the second visit is free.
Ready to talk through your San Bernardino project? Call Benson ADU Builders at (903) 568-7222 for a free, written estimate. We will walk the site with you, name real prices, and put everything in writing before a single shovel turns.
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 San Bernardino 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.
