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 Westminster
When you’re planning a remodel in Westminster, the first question is usually simple: who can handle the whole thing without you chasing four different trades? That’s what we do at Square One Builders. We’re a full-scope General Contractor team working across Westminster from Westminster‘s 1950s postwar tracts off Bolsa Avenue to the newer infill pockets near Westminster Boulevard and Beach. One contract, one accountable team, and straight answers on cost before walls ever come down. Call (877) 688-9930 to talk through your project.

Why Square One Builders Is Westminster’s Preferred General Contractor Company
Westminster homeowners keep calling us for the same reason: we open walls on 60-year-old houses every week and we know what’s behind them. That matters more in Westminster than almost anywhere else in Orange County, because the city’s housing stock is dominated by 1950s and early-1960s tract homes that share a predictable set of issues – outdated wiring, undersized framing, and waterproofing failures that no one can see until demolition starts. Homeowners here who’ve been burned by surprise change orders appreciate that we inspect first and write allowances into the contract up front.
Brent Calloway, our owner, has built Square One Builders around a single idea: a remodel should not require the homeowner to become a general contractor themselves. You don’t coordinate the roofer, the window installer, and the cabinet shop. We do. That’s why Westminster customers come back for second projects and refer neighbors in the 92683 and 92655 zip codes. Our reputation in the area is built on projects that pass inspection the first time and budgets that hold because we planned for what we’d find.
Styles & brands we work with







Hire a General Contractor in Westminster
Hire a General Contractor when the scope of your Westminster project touches more than one trade – because that’s when finger-pointing starts and schedules slip. A full kitchen remodel in Westminster runs $14,000 – $45,000, a bathroom remodel $9,000 – $28,000, and a home addition $45,000 – $130,000 depending on how much structural and systems work the house needs. Older Westminster homes almost always need more than the visible finishes suggest.
Our process in Westminster starts with a pre-bid inspection. We walk the property, check the attic and crawlspace where possible, and talk through what a permit will trigger. Then we write allowances for wiring, framing, and waterproofing directly into the contract. Not as vague “contingency” language – as real line items with real dollar figures.
Inspection-First Bidding
Most Westminster remodels hit surprises because the bidding contractor never looked behind the drywall. A 1957 ranch off Bolsa Avenue with cloth wiring and 2×6 ceiling joists will not support a modern open-plan kitchen without reinforcement. We price that reality before you sign.
Written Allowances, Not Ambiguity
Every Square One Builders contract in Westminster includes allowances for code upgrades. If waterproofing needs to be added to a shower surround or a panel needs replacement, the allowance covers it. If the allowance isn’t needed, you don’t pay it.
General Contractor Services in Westminster
General Contractor Services in Westminster mean something specific here: full-scope management of remodels, additions, and ADUs on lots that are tighter and older than what you’ll find in Fountain Valley or Huntington Beach. A small kitchen remodel in Westminster runs $9,000 – $20,000, a walk-in shower installation $4,500 – $12,000, and a garage conversion $30,000 – $80,000. Every one of those numbers assumes an older home with code triggers.
We also handle roof replacement ($8,000 – $20,000), window replacement ($4,500 – $15,000), paver patio installation ($3,500 – $11,000), and vinyl fence installation ($3,500 – $9,000). The point is that you do not need a separate contractor for any of it. One team, one schedule, one point of contact.
Full-Scope Remodels
Kitchens, primary bathrooms, whole-home updates – we manage demolition, structural work, plumbing, electrical, cabinetry, countertops, and finish trim as a single scope. For Westminster homeowners, that’s the difference between a three-month project and a nine-month one.

Additions and ADUs on Tight Lots
Westminster’s postwar lots run small – often 5,000 to 6,500 square feet. An addition or second-story pop-top will push against setback and lot-coverage limits. Our team handles survey and zoning clearance with the City of Westminster before framing begins, so you’re not three months into design and finding out it can’t be built as drawn.

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.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Westminster
Square One Builders is a General Contractor, not a brand sales team – but we spec materials from manufacturers we trust to hold up in coastal-inland Orange County conditions. For Westminster roofing projects, we typically specify GAF, CertainTeed, or Owens Corning. For exterior siding that stands up to Santa Ana winds and the occasional winter storm, James Hardie fiber cement is our default. We also stock common local parts and materials for Westminster jobs so turnaround stays tight when you’re mid-project and need a specific flashing detail or trim profile. We spec the right material for your project, not whatever happens to be on sale at a big-box store.
See the difference
Before
After
Before
After
Before
AfterCommon General Contractor Problems We See in Westminster Homes
- Cloth and aluminum wiring from the 1950s and 60s. Westminster tract homes built before roughly 1965 often have wiring that will not pass inspection once walls are open. A kitchen remodel that appears cosmetic on the surface turns into a rewire when the inspector sees what’s actually there.
- Undersized ceiling joists failing load-bearing requirements. We see 2×6 ceiling joists on 24-inch centers in older ranch homes throughout Westminster. Modern codes for open-concept layouts and second-story additions require more. This is not something you can guess at – it requires a structural review.
- Failed waterproofing in original bathrooms. Sixty-year-old shower pans and tile surrounds in Westminster leak, and the damage is usually hidden until demolition. Opening up a 1960s primary bathroom almost always reveals at least some subfloor or stud repair.
- Setback and lot-coverage complications on tight lots. Blocks off Bolsa Avenue and around the Westminster Mall are dense. An addition that clears zoning in Huntington Beach will not necessarily clear in Westminster. Survey and zoning clearance have to happen early, not after the architect draws the plans.
Pricing for General Contractor in Westminster, CA
Westminster pricing is shaped by the age of the housing stock and the reality of what permits trigger. Here are the ranges we quote most often for Westminster projects:
| Project Type | Typical Westminster Range |
|---|---|
| Kitchen Remodel | $14,000 – $45,000 |
| Bathroom Remodel | $9,000 – $28,000 |
| Home Addition | $45,000 – $130,000 |
What moves these numbers is mostly hidden condition. A kitchen in a 1962 ranch with original wiring will land higher than the same kitchen in a post-1980 home. We write allowances for exactly those unknowns so you are not absorbing cost surprises after demolition. Every Westminster estimate is free, and we’ll walk you through the line items before you sign anything. Call (877) 688-9930 to schedule yours.
We Also Serve Cities Near Westminster
Square One Builders works throughout central and coastal Orange County. Beyond General Contractor in Westminster, we serve Midway City, Garden Grove, Stanton, and Huntington Beach. If your project sits near the 22 or 405 freeways, chances are we’re already working in your neighborhood.
Serving Westminster, CA — Our Local Coverage Area
We’re based in the Westminster 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 Westminster
You should expect outdated wiring, framing that may not meet today’s load-bearing codes, and waterproofing that has failed quietly for years. In Westminster’s 1950s tract homes, we routinely find cloth wiring, undersized joists, and rotted subfloor once demolition starts. That’s why we write allowances into the contract before work begins, so these discoveries are planned for rather than billed as surprises. Call (877) 688-9930 to schedule an inspection-first estimate.
Westminster’s postwar lots are small, often 5,000 to 6,500 square feet, and additions routinely push against setback and lot-coverage limits. That means survey and zoning clearance with the City of Westminster has to happen before framing starts, not as an afterthought. Our team handles those approvals as part of the pre-construction scope. Call (877) 688-9930 and we’ll tell you what your specific lot will allow.
Yes. In Westminster, any remodel that touches electrical, plumbing, or structural elements requires a permit, and the inspection that follows will look at everything the original 1950s or 60s builder installed. We pull all permits and schedule all inspections as part of our General Contractor scope – you don’t deal with the building department directly. Call (877) 688-9930 to talk through what your project will trigger.
We price the surprise, put it in writing, and get your approval before we touch it. Most Westminster remodels have at least one hidden issue – wiring, framing, water damage – and our allowance structure means the change order is covered by a line item you already understood when you signed. Nothing gets done without your written sign-off. Estimates are free, so call (877) 688-9930 to see what this looks like for your project.
We source from KraftMaid and Wellborn for cabinetry, and Cambria, Silestone, and Caesarstone for countertops, among others. Our material portfolio spans 50+ manufacturers across every trade, which means we can offer options at multiple price tiers within the same category without you switching contractors. Call (877) 688-9930 and we’ll help you spec the right material for your Westminster home.
Written by Brent Calloway, Owner at Square One Builders, serving Westminster since day one.