Building Right in San Mateo Starts Underground
San Mateo's construction boom — from Downtown mixed-use developments to backyard ADUs in Hillsdale — requires plumbing systems designed for local conditions. High water tables near the bay, expansive clay soils in the hills, and strict municipal codes mean your plumbing contractor needs deep local knowledge.
Whether you're a general contractor coordinating a multi-unit Bay Meadows project or a homeowner adding an ADU to your San Mateo Park property, GB Plumbing delivers code-compliant installations that pass inspection the first time.
New Construction Plumbing Services
San Mateo's Unique Building Challenges
ADU Boom Requirements
San Mateo's relaxed ADU rules have sparked a building wave in Hillsdale and Baywood. Each ADU needs properly sized supply lines, independent shutoffs, and sewer connections that meet current capacity requirements.
High Water Table Zones
Properties near Shoreview and the bay face elevated groundwater that affects underground pipe installation. We use appropriate bedding materials and joint methods to prevent infiltration issues.
Downtown Mixed-Use Code
Downtown San Mateo's growing mid-rise projects require commercial-grade systems with backflow prevention, grease interceptors, and fire suppression connections — all coordinated through San Mateo's building department.
Our New Construction Process
Plan Review & Permits
We review architectural plans, size systems per fixture count, and submit permit applications to the City of San Mateo building department.
Underground & Slab Rough
Sewer and water lines installed below grade before concrete pour. Pressure tested and inspected per San Mateo municipal code.
Top-Out & Wall Rough
Supply, waste, and vent lines routed through framing. Gas piping installed. All tested and ready for city rough inspection.
Finish Trim & Final
Fixtures, faucets, water heaters, and appliance connections installed after drywall. Final inspection and system commissioning.
San Mateo New Build? Start with the Right Plumber.
From permit to punch list, GB Plumbing handles every phase of your San Mateo construction project's plumbing system.
(650) 235-6443Our Happy Clients
Real people. Real results. See why homeowners across the San Francisco Bay Area trust GB Plumbing for all their plumbing needs.
🇺🇸 🇧🇷 🇪🇸 We speak English, Portuguese and Spanish

"They plumbed our entire ADU — on schedule, on budget, passed inspection first try. Can't ask for more."
— Hillsdale ADU Owner Google Review
"As a GC, I need plumbers who show up on time and pass inspections. GB delivers every single project."
— Bay Meadows Contractor Google Review
"Our custom home build went smoothly thanks to GB. Every phase was clean, professional, and inspected."
— San Mateo Park Homeowner Google Review
"Added a second bathroom to our Baywood home. GB handled everything from permits to final fixtures."
— Baywood Resident Google Review
"Excellent communication throughout our multi-unit build. They coordinated perfectly with other trades."
— Downtown Developer Google Review
"Professional from start to finish. Our kitchen remodel plumbing was flawless."
— Fiesta Gardens Homeowner Google Review
