San Mateo / Bathroom remodeling
Bathroom Remodeling in San Mateo
The typical San Mateo home dates to 1963. Plan the bathroom around what is behind the walls.
Two in three San Mateo homes were built before 1980. We remodel bathrooms here with the city's over-the-counter review, its inspection rules and the older plumbing and wiring planned before demolition, under one licensed contractor.
SAN MATEO AT A GLANCE
What is different about remodeling in San Mateo.
San Mateo runs its permits through an online portal with a virtual counter, inspects only on next-day requests, and has one of the older housing stocks on the Peninsula. All three change how a bathroom is planned.
- 1963
- median year a San Mateo home was built
- 103,013
- residents, 2024 Census estimate
- 1
- business day to respond to a virtual counter submittal
Permits
Building Division, online first
Applications, payments and resubmittals go through the Customer Self-Service portal. Minor remodels can be reviewed at a virtual over-the-counter appointment.
(650) 522-7172Online Permit Center ↗Inspections
Next day, by 3pm
Requests close at 3pm for next-day inspections; same-day requests are not accepted. Inspectors call before 9am with a 2-hour window.
Building inspections ↗Utilities
PG&E plus WestLight Energy
PG&E delivers power and gas; WestLight Energy, formerly Peninsula Clean Energy, supplies the electricity and pays the heat pump water heater rebate.
WestLight rebates ↗Older homes
Knob and tube needs sign-off
San Mateo lets existing knob and tube wiring stay only in listed condition and certified by a licensed electrician before it is covered; deteriorated runs must be replaced.
San Mateo: checklists, guidelines and forms (kitchen remodel guide) ↗WHAT SAN MATEO CHECKS IN A BATHROOM
Quick review, if the plans are right.
San Mateo reviews bathroom remodels, even with wall changes, over the counter or at a virtual appointment when no structural calculations or fire review are needed. The plans still have to show the existing and proposed layout with every electrical, plumbing and mechanical device. Beams, structural changes or fire review move the job to full plan check.
Ventilation
San Mateo requires a 50 CFM exhaust fan in every bathroom remodel unless the existing ceiling stays, even with an operable window, on its own switch.
Shower and glass
Shower doors at least 22 inches wide and opening outward, safety glazing at tubs and showers, and the door or rod installed before final.
Drain and vent
Drain piping is water- or air-tested for 15 minutes. ABS is not allowed on the exterior except vents above the roof, or in homes over 2 stories.
Toilet clearance
30 inches of width, 15 on each side of center, and 24 inches clear in front of the bowl. Concealed slip joints need a 12 inch access door.
Electrical
A dedicated 20 amp circuit when outlets are added, GFCI and tamper-resistant outlets, one within 36 inches of each basin, and damp-rated lights near the tub.
Water heater
A water heater replacement is an express permit in San Mateo. WestLight Energy pays $3,500 for a gas-to-heat-pump switch.
COUNTER OR FULL REVIEW
Which review your bathroom gets.
San Mateo's list of projects eligible for over-the-counter and virtual review, revised November 2025, decides how fast a bathroom permit moves.
Over-the-counter review fits when
- A bathroom or kitchen remodel uses conventional framing, even with wall changes
- No structural calculations are required
- No fire review is required
- The plans can be reviewed in about 30 minutes
Full review when
- Beams or engineered framing are needed
- The property has a code enforcement case or stop work notice
- Several building permits were recently opened on the property
- The work affects zoning or the public right of way
Every submittal shows
- A written scope of work and a sheet directory
- Owner name, address and parcel number
- Designer's name, address and phone
- Existing and proposed plans with all electrical, plumbing and mechanical devices
Planning the work
How a San Mateo bathroom project runs.
Site visit
Free visit. Layout, wiring age, panel capacity, the water heater and the drain and vent routes.
Plans and virtual review
Existing and proposed plans submitted through the CSS portal for a virtual over-the-counter review.
Rough-in
Drain test, framing and electrical inspected before tile, requested by 3pm for the next day.
Finishes and final
Fixtures, shower door, alarms and final inspection, then rebate paperwork within 90 days.
WHAT TRIPS UP SAN MATEO REMODELS
Problems San Mateo homeowners run into, and how we plan around them.
From the city's remodel guides, inspection rules and permit pages.
Opening a wall reveals knob and tube wiring.
In homes this age we plan for it: existing runs are certified by a licensed electrician before cover, or replaced where they are worn.
New bathroom circuits overload an older service.
A load calculation comes first; if a service upgrade is needed, San Mateo issues it as an express permit, and we coordinate PG&E.
An inspection request misses the cutoff and costs a day.
Requests go in before the 3pm deadline with the on-site contact number, as the city asks.
A replacement fan is skipped because the room has a window.
San Mateo requires the 50 CFM fan in every remodel unless the old ceiling stays, so it is in the plan from the start.
The rebate is rejected because the permit does not name the water heater.
The permit description names the heat pump water heater, as WestLight requires for its rebate.
Sources: cityofsanmateo.org Bathroom and Kitchen Remodel Guides, building inspections and express permit pages; westlightenergy.org rebate terms.
WESTLIGHT ENERGY
Rebates that fit a San Mateo bathroom.
San Mateo does not run its own appliance rebates, so WestLight Energy's are the ones that apply. Applications are due within 90 days of installation, with a copy of the city permit.
WestLight
Gas to heat pump water heater
$3,500
For replacing a gas water heater. Up to two per account.
WestLight
Electric to heat pump water heater
$500
Replacing an electric-resistance water heater.
WestLight
Panel upgrade bonus
$1,000
One per account, added to a heat pump water heater or heat pump HVAC rebate.
WestLight
CARE or FERA customers
$1,000 extra
Per heat pump water heater or heat pump HVAC rebate, up to $4,000 per account.
Amounts from westlightenergy.org, October 2026. WestLight announces changes at least one month ahead.
Do I need a permit to remodel a bathroom in San Mateo?
Yes. San Mateo requires building permits to alter or repair a structure and plumbing permits for any fixture or piping change. A bathroom remodel, even with wall alterations, can be reviewed over the counter or virtually when it uses conventional framing without structural calculations and needs no fire review.
How fast can I get a bathroom permit in San Mateo?
Often within a few business days. After a complete virtual over-the-counter submittal, staff respond within one business day to schedule the review, and the permit is issued within one business day of paying the fees. Plan checkers hold these reviews Monday to Friday, 9am to noon.
Does a bathroom remodel in San Mateo need an exhaust fan?
Yes, at least 50 CFM, unless the existing ceiling is left in place. The city's bathroom guide applies this even when the room has an operable window, and the fan and light need separate switches, even on a combination unit.
How do I schedule a building inspection in San Mateo?
Through the Customer Self-Service portal, by 3pm the day before. Same-day requests are not accepted, the inspector calls before 9am with a 2-hour window, and inspectors can switch to a virtual inspection when they choose.
Can I use ABS drain pipe in a San Mateo bathroom?
Not everywhere. San Mateo's bathroom guide does not permit ABS in residential buildings over 2 stories, or on the exterior except vent pipes above the roof, which must be protected with latex paint.
Is there a rebate for a heat pump water heater in San Mateo?
Yes. WestLight Energy, formerly Peninsula Clean Energy, pays $3,500 to replace a gas water heater with a heat pump model, plus $1,000 for a panel upgrade. A city permit naming the water heater is required with the application.
