Skip to main content

Fire Codes

San MAteo COunty Wildfire Fire Codes 4291

Fire codes in San Mateo County set minimum standards for defensible space, access, water supply, and construction so that buildings can withstand wildfire and firefighters can reach them. The standards below are general references; requirements vary by jurisdiction, so always confirm with the fire agency responsible for your property before planning a project.

Which code applies: California adopts a new statewide code every three years, and local agencies adopt it with their own amendments, often stricter. Wildfire construction standards for new buildings in fire hazard zones are in California Building Code Chapter 7A; see our California WUI code information page for the state framework.

General Standards Reference

Defensible Space and Vegetation

  • Defensible space: 100 feet of defensible space (or to the property line), organized in zones, is required around structures in the SRA and designated fire hazard zones. See defensible space requirements.
  • Roadside clearance: flammable vegetation cleared 10 feet from roadway edges with 13 feet 6 inches of vertical clearance, so engines can pass and roadsides do not carry fire.

Construction

  • Roofs: Class A fire-rated roofing is the standard for new construction in fire hazard areas and the right choice for every re-roof in the county. See fire-resistant roofing.
  • Spark arresters: required on all chimneys and outdoor fireplaces: noncombustible heavy wire mesh with openings between 3/8 inch and 1/2 inch.
  • Ignition-resistant components: jurisdictions enforce Chapter 7A requirements for vents, eaves, siding, windows, doors, and decking on new construction and qualifying remodels in designated zones.

Access and Roads

  • Address identification: plainly legible from the street, numbers at least 4 inches high on a contrasting background. Streets and roads identified with approved signs.
  • Width and clearance: fire apparatus access with an unobstructed width of at least 20 feet and vertical clearance of 13 feet 6 inches, kept clear of parked vehicles and vegetation.
  • Gates: security gates require fire department approval and an approved means of emergency operation.
  • Bridges: constructed and maintained to carry fire apparatus, with load limits posted at both entrances.

Water Supply

  • Storage: minimum water supply for new dwellings up to 3,600 square feet capable of flowing 100 gallons per minute for 2 hours (10,000 gallons), where hydrants are not available.
  • Sprinklers: automatic fire sprinklers are required in new residential construction statewide and may be required in remodels; contact your local agency.
  • Hydrants: accessible at all times with 3 feet of clearance around the perimeter.

Fire Agencies Serving San Mateo County

Wildfire code enforcement in the county involves state, county, district, and city agencies. Contact the agency for your address: