A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across San Bernardino
Adding square footage to a San Bernardino home usually costs between $120,000 and $380,000 depending on scope, and a garage conversion or single room addition lands on the lower end while a full second-story runs higher. We’re Sutton ADU Builders, and we’ve built enough additions in San Bernardino to know exactly what the city’s plan check will flag before you’ve spent a dime on engineering. Call (472) 248-8213 for a free estimate, and we’ll walk your lot with you before pricing anything.
What makes San Bernardino different from, say, Loma Linda or Rialto is the housing stock. Drive through the neighborhoods north of Base Line or around Perris Hill and you’ll see homes from the 1920s, 1930s, and 1940s sitting on foundations that were never designed to carry a modern addition. We know those foundations. We know which ones will need an engineer’s letter before the city stamps your plans, and we know how to price that work honestly instead of surprising you at permit time.
Our crews have framed additions on streets from Del Rosa to Arrowhead, and we schedule work across San Bernardino’s 92401, 92404, 92405, and 92410 zip codes every week. If you’re considering a room addition, garage addition, or bathroom addition, the fastest way to get real numbers is to call us at (472) 248-8213. The estimate is free, and the price we give you is the price you get before work begins.
Why Sutton ADU Builders Is San Bernardino’s Preferred Home Addition Contractor
We’ve been doing this under the Sutton name since 2006, and the reason San Bernardino homeowners keep calling us back isn’t charisma. It’s the written guarantee. Every addition we build carries the 365-Day Done Right Promise: if any element of the finished work fails within one full calendar year from project completion, we return and make it right at no charge. That’s printed on your contract, not mentioned in passing.
The second reason comes down to who shows up at your door. Every technician on a San Bernardino job is background-checked and identity-verified under the Threshold Verified standard. Before the crew arrives, you get the name and photo of every person coming onto your property. They arrive in a clean, marked uniform and show a photo ID badge at the door. For homeowners with young kids or older residents who are home alone during the day, that’s not a marketing line. That’s the reason they call us.
We’re the ADU-specialist member of the Threshold Group family, and our dispatch for San Bernardino is coordinated from the Inland Empire office. When you call (472) 248-8213, a live person answers. No voicemail tree. Whether you’re asking about a garage addition near San Bernardino High School or a second-story addition up toward Verdemont, you’ll talk to someone who can give you straight answers. And if you’re still comparing your options, our Home Addition Contractor team can walk you through the full process from plan check to final inspection.
Garage Addition Contractors in San Bernardino
Garage Addition Contractors in San Bernardino handle two distinct jobs: extending an attached garage to create living space, or converting a detached garage into a finished room. A garage addition in San Bernardino typically runs $45,000 – $120,000 depending on whether you’re extending the footprint or converting existing space, and whether the city requires seismic detailing. The critical thing to understand is that once a garage becomes habitable, it stops being a garage in the eyes of the building department. Title 24 energy compliance kicks in, and on older lots near Base Line and Highland Avenue, you may be required to shore or seismically detail the existing structure before the conversion passes.
Attached vs. Detached in San Bernardino
An attached garage addition off the side of your house shares a wall and usually a roof line, which means the framing crew has to tie into your existing stucco and match your roofline. If you own a 1930s bungalow, that’s where the labor hours add up. Matching old stucco texture and flashing an old roof to new framing is detail work, and it’s the part of the job that gets underestimated in cheap bids.
When a Detached Conversion Makes Sense
A detached garage conversion in San Bernardino gives you more privacy from the main house, which a lot of homeowners want when the addition is for an aging parent or a rental. But the foundation under a 1940s detached garage is often a slab that was never engineered for living space. We’ll inspect it before we price it, so the estimate you get covers the real work.
Bathroom Addition Contractor in San Bernardino
A Bathroom Addition Contractor in San Bernardino typically builds a 40-to-80-square-foot full bathroom for $35,000 – $80,000 depending on fixture level and whether plumbing has to be extended through an existing slab or raised foundation. The most common scopes we take on are adding a second bath to a two-bedroom home in the Perris Hill area, or putting a private bath into a primary suite addition off the rear of a house near the University District. When you’re adding a bathroom, the rough-in inspection is what determines whether the job moves on time. San Bernardino inspectors want the DWV (drain, waste, vent) lines exposed and the P-trap set before you close anything up.
Slab vs. Raised Foundation Plumbing
If your San Bernardino house sits on a raised foundation, extending plumbing lines is usually straightforward: the plumber works from underneath. If you’re on a slab, the crew has to cut concrete, run new lines, and patch. That’s a $3,000 – $8,000 difference on a typical bathroom addition, and we’ll tell you which one you have before we quote.
Venting and Code Requirements
San Bernardino follows the California Plumbing Code, and every new bathroom needs a vent to the roof or an air admittance valve where the city approves it. On older homes, we sometimes tie into an existing vent stack if it’s within the required distance. If it isn’t, expect a new roof penetration, which adds a day of roofing work and a small stucco patch.
Trusted Brands We Service in San Bernardino
If you’re considering a prefab or modular approach to your home addition, we’re authorized to work with Abodu, Cover, Dvele, and Mighty Buildings, and we can give you honest guidance on which product line actually fits your lot and budget. Prefab isn’t always cheaper in San Bernardino once you factor in crane access on narrow lots near Shandin Hills or foundation work on sloping sites in the foothills. But for a detached unit on a flat yard, it can cut months off the schedule. We also work with James Hardie exterior systems when you want a siding match on an addition rather than a stucco patch job.
Common Home Addition Contractor Problems We See in San Bernardino Homes
- Rubble and brick foundations that fail plan check. San Bernardino’s pre-1940s core neighborhoods, especially around the Base Line corridor, sit on shallow rubble-stem or brick foundations that a prescriptive addition plan simply cannot address. The city will require a structural engineer’s site-specific foundation letter before they’ll stamp your permit, and if you started with a prescriptive plan set, you’re now paying for engineering retroactively.
- Garage additions treated as nothing more than a remodel. A detached garage conversion in San Bernardino is not a minimum-scale remodel. Once that space becomes habitable, Title 24 energy and possibly shoring/seismic detailing come into play. Homeowners who budget for drywall and flooring get surprised when the engineer says the existing slab isn’t adequate.
- Stucco and roof tie-in labor between old framing and new. Joining new framing to a 1930s stucco wall almost always forces a full stucco patch, flashing rework, and sometimes a partial roof rebuild at the transition. If your estimate doesn’t line-item that work, you’ll find it in a change order later.
- Permit stall-outs on older foundations. We’ve seen additions sit for six weeks because a footing detail wasn’t deep enough to carry the new roof load, and the engineer had to re-detail the connection. On a 1930s bungalow near the Base Line corridor, our own framing scope paused for exactly that reason. Once the revision cleared, rough-in and inspection passed and we closed out with a full stucco match on the original wall.
Pricing for Home Addition Contractor in San Bernardino, CA
Here’s what we see in San Bernardino right now. A single room addition of 200 – 350 square feet runs $120,000 – $190,000. A second-story addition ranges $220,000 – $380,000 depending on whether we’re reinforcing the first-floor walls and foundation. A garage conversion lands between $45,000 and $120,000 based on seismic and Title 24 scope. A bathroom addition is $35,000 – $80,000. A bump-out of 50 – 100 square feet to expand a kitchen or bedroom is $60,000 – $110,000. Sunroom additions run $50,000 – $140,000 depending on glazing and whether it’s conditioned space.
What moves the price mid-project in San Bernardino? Foundation surprises, which we’ve covered. Stucco matching and roof tie-in labor, which we’ve also covered. And permit revisions, which happen when the original plan set doesn’t match what’s actually under your house. We send a written line-item price before any work begins, and we don’t pass scope changes to your bill silently. Call (472) 248-8213 for a free estimate on your specific project.
We Also Serve Cities Near San Bernardino
While this page speaks to San Bernardino homeowners, we regularly build additions in Loma Linda, Highland, Rialto, and Colton. If you’re just outside the city line, our San Bernardino service area covers your neighborhood too. Call us and we’ll confirm scheduling for your street.
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 Home Addition Contractor in San Bernardino
Yes. A home addition attached to your existing house is permitted through a building permit for the addition itself, while a detached ADU requires its own separate building permit. In San Bernardino, the two are regulated differently, and the city will not combine them into a single permit even if you’re building both. Call (472) 248-8213 and we’ll tell you exactly which permits your project triggers.
Because the foundation under a pre-1940s home was often built as a shallow rubble-stem or brick footing, which falls outside standard prescriptive addition plan sets. San Bernardino’s building department will require a structural engineer’s site-specific foundation letter before they’ll stamp the plans, and that engineering review adds time to the front end. We account for it in our schedule from the first visit.
Foundation discoveries, stucco and roof tie-in labor, and permit revisions. On older homes near Base Line, a shallow footing can force an engineer to re-detail the connection, and that pauses framing. We price those known risks before work begins so the written price you get is the price you can rely on.
A single room addition typically runs 4 – 7 months from the first call through plan check, permitting, construction, and final inspection. A second-story addition can run 8 – 12 months. The San Bernardino plan check queue and any engineering letters for older foundations are the variables that move the calendar most.
Yes. We’ve matched stucco texture and roofline transitions on 1920s and 1930s homes throughout San Bernardino, including a full stucco match on the original wall when we framed an addition off a 1930s bungalow near the Base Line corridor. We use James Hardie lap siding or a stucco patch depending on what the existing wall calls for.
Call Sutton ADU Builders for Your San Bernardino Home Addition
If you’re planning a home addition in San Bernardino, you want a builder who will tell you what the city requires, what the old foundation can carry, and what the job will actually cost before you sign anything. That’s how we work. Call (472) 248-8213 to schedule your free estimate, and you’ll get a written price before any work begins. If you want to meet the crew first, we’ll send their names and photos ahead of time. That’s the Threshold Standard, and it’s how every San Bernardino project starts.
Written by Miles Hartwell, owner at Sutton ADU Builders, serving San Bernardino since 2006.
