Kitchen remodeling
Bathroom remodeling
Home additions & ADU
Roofing
Windows & doors
Driveway & pavers
FenceFree written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable General Contractor Across Muscoy
If you own a home in Muscoy, you already know the drill. You call a contractor for a kitchen or bath quote, and the first thing you hear is confusion about whether your property falls under City of San Bernardino rules or County of San Bernardino rules. Square One Builders works in Muscoy constantly. We understand that Muscoy is an unincorporated county island, which means your permits, inspections, and parcel history all run through the county, not the city. That single fact changes how a remodel gets scoped, priced, and permitted. Call us at (877) 688-9930 and you’ll talk to someone who already knows your situation.

Why Square One Builders Is Muscoy’s Preferred General Contractor Company
Most Muscoy homeowners we meet have dealt with a contractor who quoted off visible finishes and never once mentioned the county’s permitting process for older lots. Our team, led by Brent Calloway, has spent years working unincorporated San Bernardino County parcels, sorting out what was legally built, what needs to be legalized, and what the county will actually sign off on. That local knowledge is the difference between a remodel that stalls at inspection and one that moves through cleanly.
We coordinate the full scope under one contract. Kitchens, bathrooms, additions, ADUs, roofing, windows, hardscaping, fencing. The homeowner never has to hire and manage separate specialists. When a Muscoy customer calls us about a kitchen remodel, they get one accountable team from demolition through final finish. That matters even more here, where a remodel often starts with opening walls and figuring out what a previous owner actually built.
Our response time to Muscoy is quick because we run jobs across the surrounding area regularly. We know 92405, we know the streets off Cajon Boulevard, and we know the rural-residential parcels that don’t look anything like a San Bernardino tract home.
Styles & brands we work with







Residential General Contractor in Muscoy
Residential General Contractor work in Muscoy means remodeling and renovating homes that are often older, wood-framed, or manufactured, sitting on generous lots with a patchwork of owner-built additions, shops, and outbuildings. When a Muscoy homeowner calls us, the job usually starts with an inspection of what’s actually behind the walls and under the floors. That’s not a sales tactic. It’s how we write a quote that won’t blow up on you mid-project.
A typical kitchen remodel in Muscoy runs $14,000 to $45,000. A bathroom remodel lands between $9,000 and $28,000. Those ranges change based on what the inspection turns up, what the county requires once walls are open, and which materials you select.
Inspection Before Quote
We don’t quote a Muscoy remodel off finish photos or a walkthrough of what’s visible. We look at the framing, the wiring, the subfloor, and the permit history on file with San Bernardino County. That means fewer surprises for you after demolition starts. It also means our quotes include written allowances for the code-driven upgrades that older Muscoy homes almost always trigger.
Older homes here routinely need electrical panel upgrades, re-framing of sagging headers, and water-damage repair once we open things up. We build those into the contract as allowances so you’re not blindsided.
County Permits Handled
Because Muscoy is unincorporated, every permit runs through San Bernardino County’s Building and Safety division. We handle the paperwork, the parcel mapping review, and the inspection scheduling. We know what the county wants to see for legalizing existing structures, and we don’t guess. The permit path in Muscoy is not the same as adjacent city limits, and guessing creates weeks of delays.
Hire a General Contractor in Muscoy
When you hire a general contractor in Muscoy, you’re hiring someone to manage every system of the project under one accountable contract. That includes structural work, roofing, plumbing fixtures, windows, cabinetry, countertops, and hardscaping if the scope calls for it. You’re not coordinating three or four separate trades with three or four separate schedules and warranties.
Most Muscoy homeowners we work with already tried the multi-contractor route on a previous project and don’t want to repeat it. The appeal of one contract is that when something goes sideways, there’s one phone number, and it’s ours. Call (877) 688-9930 to talk through your project and get a free written estimate.
Full-Scope Remodels
Kitchen and bathroom remodels are our most common Muscoy jobs, but the scope often grows once we inspect. A homeowner calls about a shower pan, and we find a wet subfloor that extends under an adjacent bedroom. That’s exactly the kind of condition we handle: one team, one plan, one change order if needed, all approved in writing before we proceed.

Additions and ADUs
Home additions in Muscoy run $45,000 to $130,000 depending on square footage, foundation work, and county requirements. Garage conversions run $30,000 to $80,000. The county’s parcel mapping and setback rules heavily influence what you can build, which is why we check parcel history before we price anything. We’re also set up to work with prefab and ADU partners like Abodu and Dvele, which most local remodelers can’t offer.
Trusted Brands We Service in Muscoy
We source and install materials from more than 50 nationally recognized brands, so a Muscoy homeowner never has to settle for whatever a single-trade contractor happens to stock. For roofing, we work with GAF and Owens Corning, the two largest U.S. manufacturers. For cabinetry we spec KraftMaid and Wellborn. For countertops, you can choose Cambria at the premium end or Silestone for a value-conscious project. We spec the right material for your project, and we keep local availability in mind so a Muscoy job doesn’t stall waiting on a backordered item.
See the difference
Before
After
Before
After
Before
AfterCommon General Contractor Problems We See in Muscoy Homes
- Cloth-wrapped and outdated wiring. Many older Muscoy homes still have original cloth-insulated wire that the county requires brought to current code once a wall is opened for a remodel. We write that upgrade into the allowance up front.
- Owner-built additions and shops with no permit history. A high share of Muscoy lots have add-ons, enclosed patios, or outbuildings that were never permitted. Before we touch a remodel, we check what San Bernardino County has on file and sort each structure into ‘existing’ or ‘legalize’ status.
- Wind and sun damage from Cajon Pass conditions. High winds funnel through the pass and the wash, and summer sun degrades roofing, sealants, and exterior finishes faster than homeowners expect. Roof replacements in Muscoy run $8,000 to $20,000, and we often find wind-lifted shingles and dry-rot around flashing.
- Wet subfloors under old shower pans and plumbing. We regularly find subfloor damage that extends beyond the visible water stain. A failing shower pan in a 1960s Muscoy home almost always means replacing more than the tile. We scope it accurately before demolition, so the change order is a written line item, not a surprise phone call.
Pricing for General Contractor in Muscoy, CA
Here’s what you should expect to budget for common Muscoy projects based on actual job costs in this market. These ranges reflect what we see across unincorporated county parcels, older homes, and the code upgrades a permit typically triggers here.
| Project | Typical Muscoy Range |
|---|---|
| Kitchen Remodel | $14,000 – $45,000 |
| Bathroom Remodel | $9,000 – $28,000 |
| Home Addition | $45,000 – $130,000 |
| Garage Conversion | $30,000 – $80,000 |
| Roof Replacement | $8,000 – $20,000 |
What moves a Muscoy quote most is what inspection turns up inside the walls. We write allowances into every contract for the upgrades the county will require, and we price any discovery in writing before we proceed. Call (877) 688-9930 for a free estimate with a written line-item quote.
We Also Serve Cities Near Muscoy
Square One Builders works throughout San Bernardino County, including San Bernardino, Rialto, Highland, and Crestline. If you’re just outside Muscoy, the same full-scope General Contractor team handles your project, and our General Contractor in Muscoy experience directly applies to the unincorporated parcels and older housing stock throughout this corridor.
Serving Muscoy, CA — Our Local Coverage Area
We’re based in the Muscoy 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 General Contractor in Muscoy
Because most older Muscoy homes were built or added onto before current code, and the county requires electrical, framing, and waterproofing upgrades once a wall is opened for permitted work. We inspect before quoting and write allowances into the contract so the quote doesn’t move on you without a signed change order. Call (877) 688-9930 for a quote that accounts for what’s behind the drywall.
From San Bernardino County. Muscoy is unincorporated, so every permit runs through the county’s Building and Safety division, not the City of San Bernardino. We handle the county parcel review, permit application, and inspection scheduling for you.
Yes, that’s a big share of our Muscoy work. We start by pulling the county’s parcel and permit records for your lot, identify what needs to be legalized versus what qualifies as existing, then scope the work and the paperwork together so you know the total cost before anything gets touched. Call (877) 688-9930 to have us check your parcel.
We spec the job to your selections and write the material allowances into the contract from the start. Since we source KraftMaid and Cambria directly, your remodel doesn’t drift when you pick the finish you actually want. The price is set around your choices, not a builder-grade default that changes later. Call (877) 688-9930 for a free estimate built around your picks.
Yes, and it should. Wind uplift through the pass and the wash requires stronger roof fastening and flashing details than a standard inland install. Summer heat means stucco and concrete need controlled drying so they don’t cure weak. We plan for both on every Muscoy project, from roof replacements to additions and hardscaping. Call (877) 688-9930 to discuss your project.
Ready to get started? Call Square One Builders at (877) 688-9930 for a free, written estimate on your Muscoy remodel. We’ll walk your property, check your permit history with San Bernardino County, and give you a real number you can plan around.
Written by Brent Calloway, Owner at Square One Builders, serving Muscoy and San Bernardino County since 2010.