Building Permit Cost in San Mateo County, CA (2026)

We're still compiling San Mateo County's full fee schedule. Use the lookup tool below for project-specific estimates.

By Joey, Founder · Last verified April 24, 2026 · How we research →

The short answer

Simple swaps (water heaters, EV chargers, like-for-like HVAC) usually run under $200. Additions, pools, and kitchen remodels are the expensive end. Confirm current rates with San Mateo County Planning and Building Department at (650) 599-7310.

Permit fees by project type in San Mateo County

Each row shows the estimated fee range for that project type in San Mateo County, the typical approval timeline, and how it compares to the California state average.

Project Est. fee in San Mateo County vs state avg Typical timeline
Deck Varies N/A about 6 weeks
Fence Varies N/A about 4 weeks
Shed Varies N/A about 4 weeks
Roof Replacement Varies N/A about 1 week
Windows and Doors Varies N/A about 4 weeks
Bathroom Remodel Varies N/A about 2 weeks
Kitchen Remodel Varies N/A about 3 weeks
Swimming Pool, Hot Tub, or Spa Varies N/A about 9 weeks
Electrical Work Varies N/A about 1 week
Plumbing Work Varies N/A about 2 weeks
HVAC Varies N/A about 2 weeks
Garage Varies N/A about 9 weeks
Room Addition Varies N/A about 11 weeks
Basement Finishing Varies N/A about 4 weeks
Retaining Wall Varies N/A about 6 weeks
Solar Panels Varies N/A about 2 weeks
Patio Varies N/A about 2 weeks
ADU Varies N/A about 9 weeks
Driveway Varies N/A about 3 weeks
Demolition Varies N/A about 6 weeks
EV Charger Varies N/A 5 business days
Generator Varies N/A about 2 weeks
Gas Line Varies N/A about 2 weeks
Water Heater Varies N/A about 1 week
Tree Removal Varies N/A about 3 weeks
Siding Varies N/A about 2 weeks
Fireplace Varies N/A about 2 weeks
Concrete Slab Varies N/A about 2 weeks

Fees are estimates based on San Mateo County's rule data and may not include sub-permits (electrical, plumbing, mechanical) required for larger projects. The "vs state avg" column compares the midpoint of each range to the California statewide average for the same project type.

How San Mateo County's permit fees are structured

Most city permit fees break down into four buckets. The exact split varies, but these proportions hold across most US jurisdictions we track.

Building permit fee~55% of total
Plan review fee~30% of total
Inspection / processingremainder
Technology / records fee$5–$15 flat

View San Mateo County's official fee schedule →

San Mateo County vs state vs national averages

Midpoint of the estimated range for a typical residential permit.

San Mateo County (this city) n/a
California state avg $232–$982
National avg (1,500+ cities) $165–$697

How to reduce your permit cost in San Mateo County

  • Ask about over-the-counter permits. Many jurisdictions issue same-day permits for simple projects (water heater swap, like-for-like windows, small sheds). Saves a full plan-review cycle.
  • Pull the permit yourself. Owner-builder permits are usually the same fee as contractor permits, minus the contractor markup. Most cities (including San Mateo County where owner-builder is allowed) let homeowners file directly.
  • Submit complete plans the first time. Resubmittals often trigger a re-review fee. A clean first submittal is typically the single biggest driver of cost and timeline.
  • Check if your project is exempt. Small fences, low decks, minor electrical, and like-for-like appliance swaps are often permit-exempt. Use our free lookup tool to check your specific project before assuming you need one.
  • Bundle related work. If you're doing multiple upgrades, applying for them together is usually cheaper than separate permits, because plan review and inspection fees are often priced per-visit.

Who to call in San Mateo County

DepartmentSan Mateo County Planning and Building Department
Phone(650) 599-7310
Emailbuildinginspections@smcgov.org
Address455 County Center, 2nd Floor, Redwood City, CA 94063
HoursMonday-Thursday 8:00 AM - 4:00 PM (closed noon-1 PM); closed Friday-Sunday
Apply onlineSan Mateo County permit portal →

Check if your project needs a permit in San Mateo County

Free instant answer with the municipal code section cited.

Check permit requirements All San Mateo County rules

Frequently asked questions

How much does a building permit cost in San Mateo County, CA?

San Mateo County permit fees vary by project type and valuation. Contact San Mateo County Planning and Building Department for current rates or use our free permit lookup tool.

Why are permit fees different in San Mateo County than other cities?

Every city sets its own fee schedule. Fees typically scale with project valuation and cover building-permit review, plan review, inspections, and a small technology or records fee. San Mateo County publishes its fees separately from surrounding jurisdictions, so the same project can cost materially more or less one town over.

Do I have to pay the permit fee even if the city denies the permit?

Most jurisdictions charge a non-refundable plan-review fee at submission, which stays with the city even if the permit is ultimately denied. The balance (permit issuance and inspection fees) is typically refunded or never collected. Confirm with San Mateo County Planning and Building Department before you file.

Can the permit fee go up after I apply?

Yes. Most cities recalculate fees once plan review is complete if the declared project valuation changes, or if additional sub-permits (electrical, plumbing, mechanical) are required. Budget for a 10–15% buffer over the estimate.

Is there a way to lower my San Mateo County permit cost?

A few practical options: file for an over-the-counter permit if your project qualifies, submit complete plans the first time to avoid resubmittal fees, pull the permit yourself instead of paying a contractor's markup, and check whether your project is exempt (small sheds, low fences, like-for-like water heater swaps often are).

Disclaimer: Fee estimates are based on San Mateo County's published rule data as of April 24, 2026. Actual fees may vary based on project valuation, sub-permits required, and city schedule updates. Always confirm current fees with San Mateo County Planning and Building Department before budgeting.