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 San Mateo
If you’re planning a kitchen remodel, bathroom renovation, room addition, or ADU in San Mateo, you’re looking at $14,000 – $45,000 for a typical kitchen, $9,000 – $28,000 for a bathroom, and $45,000 – $130,000 for an addition, with some scopes climbing higher depending on what’s behind your walls. We’re Gold Star Contractors, led by Noel Carranza, and we run full-scope general contracting for homeowners across San Mateo’s 94401, 94402, 94403, and bayfront-adjacent 94404 neighborhoods. One contractor. Every system. No handoff gaps. Call (833) 382-8544 to schedule a free estimate, and we’ll put actual numbers on your scope.
Why Gold Star Contractors Is San Mateo’s Preferred General Contractor Company
San Mateo homeowners keep calling us because we understand what this city’s housing stock actually throws at you. Most homes here were built before 1960. That means pier-and-post foundations in the hills, old bay fill on the flats, and wiring and plumbing that haven’t been touched since the Eisenhower administration. Our General Contractor team opens walls expecting to find knob-and-tube, galvanized pipe, and non-conforming prior additions, and we price that reality into the contract before we start swinging hammers.
Noel Carranza built Gold Star Contractors around a simple idea: the homeowner shouldn’t have to coordinate five different trades and hope they talk to each other. We specify the brand, manage the install, and stand behind the result. When a San Mateo homeowner calls us about a second-story addition near downtown or a garage conversion in 94404, they get one accountable team from first inspection to final walkthrough.
We’re not a remote operation. We work in San Mateo zip codes 94401, 94402, and 94404 every week, and we know the city’s planning culture. San Mateo’s discretionary review process rewards contractors who submit clean, complete packages the first time, and our team knows what Planning expects before you pay for a third resubmission.
Styles & brands we work with
Construction Company in San Mateo
Construction Company work in San Mateo means something different than it does in the newer East Bay suburbs. Here, you’re almost never building on a blank lot. You’re lifting a 1930s Spanish stucco bungalow off its pier-and-post foundation to add a second story, or you’re carving an ADU out of a garage that’s been standing since Truman was in office. A home addition in San Mateo runs $45,000 – $130,000, while an ADU project typically lands between $90,000 and $220,000 depending on site conditions, foundation work, and whether you go site-built or prefab with manufacturers like Abodu or Dvele.
The lot-splitting and remodel-in-place reality of this city means nearly every project triggers planning review, and that review timeline has to be baked into your schedule and your draw schedule. We’ve seen permitted additions stall mid-rough-in because nobody accounted for the city’s submittal calendar, and the punch list slid straight into the rainy season.
Foundation and Drainage Scoping
San Mateo’s coastal-to-bay soil gradient means the same foundation detail that works on a hillside lot off Alameda de las Pulgas can fail on the expansive bay-fill flats near 94404. We scope foundations and waterproofing per lot, not per city. It’s the difference between a dry crawlspace and a rework bill.
Permit-Ready Submittals
Our team prepares drawings, structural calculations, and product spec sheets the way San Mateo’s planners expect to see them. We pull the permits, we sit the inspections, and we don’t close a single wall until the inspector signs off.
Remodeling Contractor in San Mateo
Remodeling Contractor work in San Mateo usually starts with a homeowner asking us to fix one room and ends with a conversation about what the home actually needs. A kitchen remodel here runs $14,000 – $45,000, a bathroom $9,000 – $28,000, and a garage conversion $30,000 – $80,000. Those ranges move when we open walls and find what prior owners left behind.
On a 1940s stucco bungalow near downtown in 94401, our crew opened the kitchen wall for a remodel and found knob-and-tube wiring and undersized framing around a load-bearing header that no prior permit had captured. We stopped, wrote the structural repair and electrical rough-in as a line-item change order with a priced allowance, got written owner approval, then scheduled the inspection sign-off before closing anything up. The bath scope ran the same way: failed shower waterproofing behind original tile got its own written change order before our tech set the new Kohler pan.
The Open-Wall Reality
Pre-war and mid-century San Mateo homes routinely surface knob-and-tube wiring, galvanized plumbing, and framing that doesn’t meet current code. We don’t treat these as surprises. We write allowances into the contract for exactly these discoveries, and any change order gets priced and approved in writing before we touch it.
Single-Team Coordination
Your remodel shouldn’t require you to play dispatcher between an electrician, a plumber, a tile crew, and a drywall finisher. From the roofline to the countertop, our crew handles the full sequence, so the tile setter isn’t waiting for the plumber who’s waiting on the framing fix.
Trusted Brands We Service in San Mateo
For San Mateo remodels, we lean on brands built for wet, marine-influenced environments. Toto toilets and bidet systems hold up to the mineral profile of Bay Area water far better than bargain fixtures, and we install a lot of them in 94401 and 94402 bathroom remodels. Schluter waterproofing membranes go under every tile shower we set, because foggy summers and wet winters don’t forgive shortcuts. American Standard and Sterling give our San Mateo customers dependable mid-range options when a full Toto suite doesn’t fit the budget. Premium materials, professionally installed. That’s the standard.
See the difference
Before
After
Before
After
Before
AfterCommon General Contractor Problems We See in San Mateo Homes
- Moisture at grade and in crawlspaces. San Mateo’s fog and winter rains keep soil damp for months. Pier-and-post foundations in 94401 and 94402 often carry decades of water damage that only shows up once we open the floor system.
- Knob-and-tube wiring behind original walls. That 1920s bungalow near downtown looks charming until we find cloth-wrapped wire in the lath. Replacing it isn’t optional once a permit is pulled, and it’s a real line item.
- Non-conforming prior additions. A previous owner finished the garage in 1972 without a permit. Now you want to convert it to an ADU, and the city needs us to reconcile the old work before approving the new.
- Soil movement on the flats. Expansive bay-fill soils near 94404 shift seasonally. Driveways crack, patios heave, and door frames bind. Foundation and drainage details that work on the hill side of El Camino frequently fail on the bay side.
Pricing for General Contractor in San Mateo, CA
Here’s what we tell homeowners in San Mateo when they ask what things cost. These are real ranges for this market, not national averages smoothed out by software.
| Project | Typical San Mateo Range |
|---|---|
| Kitchen Remodel | $14,000 – $45,000 |
| Bathroom Remodel | $9,000 – $28,000 |
| Home Addition | $45,000 – $130,000 |
| ADU Construction | $90,000 – $220,000 |
| Garage Conversion | $30,000 – $80,000 |
Your final number depends on what’s behind the walls, what foundation work the lot requires, and which brands you select from our 50-plus manufacturer partnerships. We give written line-item estimates, and we don’t change the price unless you approve a change order in writing first. Call (833) 382-8544 to schedule your free estimate.
We Also Serve Cities Near San Mateo
As a General Contractor in San Mateo serving the whole mid-Peninsula, we regularly run projects in Highlands-Baywood Park, Foster City, Belmont, and Hillsborough. Call (833) 382-8544 and we’ll send someone out to look at your property, wherever you are on the Peninsula.
Serving San Mateo, CA — Our Local Coverage Area
We’re based in the San Mateo 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 San Mateo
Because pre-war and mid-century San Mateo homes routinely hide knob-and-tube wiring, galvanized plumbing, and undersized framing that doesn’t meet current code. We handle this by inspecting before we quote, writing priced allowances for known-risk items, and issuing written change orders for anything unexpected, so the price moves with your signature, not without it. Call (833) 382-8544 to get an exact number for your home.
Yes. Any remodel that opens walls, moves plumbing, changes electrical, or alters framing in San Mateo requires a permit, and the city’s discretionary review process means unpermitted work gets flagged when you try to sell or refinance. We pull permits, schedule inspections, and close out every project with sign-offs in hand. Call (833) 382-8544 and we’ll walk you through what your specific scope triggers.
The coastal-to-bay soil gradient means hillside lots off Alameda de las Pulgas sit on heavier clay, while flats near 94404 rest on expansive old bay fill. A drainage detail that handles hillside runoff may not hold on the flats, so we scope foundations and waterproofing per lot, not per city. Call (833) 382-8544 to schedule a foundation review before you commit to an addition.
We write allowances into the contract for the known unknowns, like knob-and-tube or failed shower waterproofing, and every change order comes as a priced line item you approve in writing before work proceeds. That means no mid-rough-in surprise bills. Call (833) 382-8544 for a line-item estimate on your addition or ADU.
We install Toto, Kohler, American Standard, and Sterling plumbing fixtures, and we use Schluter waterproofing systems under tile showers. Countertops come from Cambria, Caesarstone, and Silestone. Cabinetry lines include KraftMaid and Wellborn. You choose the material, and we manage the install. Call (833) 382-8544 for a free estimate.
Written by Noel Carranza, Owner at Gold Star Contractors, serving San Mateo and the mid-Peninsula.