Brush Clearance: San Mateo vs South San Francisco
How do brush clearance rules compare between San Mateo, CA and South San Francisco, CA?
San Mateo has fewer restrictions than South San Francisco.
San Mateo, CA
San Mateo County
Properties in fire-prone areas of San Mateo must maintain defensible space under California PRC 4291. The San Mateo Consolidated Fire Department enforces vegetation management requirements. Hillside properties on the western slopes are subject to enhanced clearance requirements.
View full San Mateo rules →South San Francisco, CA
San Mateo County
Properties in the Wildland-Urban Interface of unincorporated San Mateo County must maintain defensible space under California Public Resources Code 4291: 100 feet of clearance around structures. CAL FIRE / San Mateo County Fire conducts defensible space inspections, and roadside vegetation must be cleared to specified clearances.
View full South San Francisco rules →Key Facts Comparison
| Fact | San Mateo | South San Francisco |
|---|---|---|
| Defensible Space | 100 feet required (PRC 4291) | - |
| Zone 1 | 0-30 ft — lean/clean/green | - |
| Zone 2 | 30-100 ft — reduced vegetation | - |
| High-Risk Areas | Western hillside neighborhoods | - |
| Fire Dept | SM Consolidated Fire | - |
| Governing law | - | California Public Resources Code section 4291 |
| Defensible space distance | - | 100 ft around structures |
| Zone 1 (home defense) | - | 0-30 ft - lean, clean, green |
| Zone 2 (reduced fuel) | - | 30-100 ft - grass cut to 4 in max |
| Roadside clearance | - | 13 ft 6 in vertical, 10 ft from road edge |
| Inspections / contact | - | San Mateo County Fire Marshal, (650) 573-3846 |
Highlighted rows indicate differences between cities.
San Mateo FAQ
Does my San Mateo property need brush clearance?
Properties in or near wildland-urban interface areas must maintain 100 feet of defensible space. Western hillside properties are most likely affected.
What does defensible space require?
Zone 1 (0-30 ft): short, well-watered vegetation, no dead plants. Zone 2 (30-100 ft): spaced and thinned vegetation to slow fire spread.
Who enforces brush clearance in San Mateo?
The San Mateo Consolidated Fire Department conducts inspections and issues notices for non-compliant properties.
South San Francisco FAQ
How much defensible space do I need in unincorporated San Mateo County?
Under California Public Resources Code 4291, you must maintain 100 feet of defensible space around structures (or to your property line): Zone 1 is the first 30 feet kept lean, clean, and green, and Zone 2 extends from 30 to 100 feet with reduced fuel and grass cut to 4 inches.
Who inspects defensible space here?
The San Mateo County Fire Marshal's Office / CAL FIRE conducts defensible space inspections in the Wildland-Urban Interface. Contact SMCFDFireMarshal@fire.ca.gov or (650) 573-3846 to schedule an inspection or report a hazard.
Do I have to clear vegetation along my road?
Yes. Roadside vegetation clearance requires removing flammable vegetation to a vertical clearance of 13 feet 6 inches and 10 feet from the edges of the roadway.
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