San Diego County, CA Environmental Rules: Defensible Space (2026)
Key Facts
- Fuel modification zone
- Up to 100 feet from building
- Zone 0 (0-5 ft)
- Non-combustible hardscape only
- Shrub height cap
- 6 feet maximum
- Tree canopy spacing
- 10-30 feet by slope
- Enforcement
- Fine up to $1,000 or jail
Summary
Unincorporated San Diego County requires a defensible space zone of up to 100 feet around every habitable building in fire hazard areas, with specific tree spacing, shrub limits, and ignition-zone landscaping standards.
A fuel modification zone shall be required around every building that is designed primarily for human habitation or use, or a building designed specifically to house farm animals. Decks, sheds, gazebos, freestanding open-sided shade covers and similar accessory structures less than 120 square feet and 50 feet or more from a dwelling, and fences more than 5 feet from a dwelling, are not considered structures for the establishment of a fuel modification zone. A fuel modification zone shall comply with the following:
(a) When a building or structure in a hazardous fire area is located 100 feet or more from the property line, the person owning or occupying the building or structure shall maintain a fuel modification zone within 100 feet of the building or structure. See Sec. 604.12 "Home Ignition Zones" See Annex D for "Fuel Modification".
(b) The fire code official may increase the fuel modification zone more than the 100 foot minimum if fuel and/or topography are determined to increase the fire hazard severity.
(c) When a building or structure in a hazardous fire area is setback less than 100 feet from the property line, the person owning or occupying the building or structure shall meet the requirements in subsection (a) above, to the extent possible, in the area between the building or structure and the property line.
(d) The building official and the FAHJ may provide lists of prohibited and recommended plants.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-141: Administrative: Current through Ord. No. 11007 (N.S.), effective 7-10-26 | Regulatory: Current through Ord. No. 11008 (N.S.), effective 7-24-26).
Full Breakdown
The County's Fire Code amendments (Sec. 96.2.604, revising Section 604 of the California WUI Code) require a fuel modification zone up to 100 feet from any habitable building or barn on unincorporated land in a State or Local Responsibility Area, Very High Fire Hazard Severity Zone, or Wildland-Urban Interface area. The property owner or occupant must maintain the zone, and the Fire Authority Having Jurisdiction can order removal of non-fire-resistant vegetation, roof litter, or overgrown trees. Mature tree canopies must keep 10 to 30 feet of horizontal separation depending on slope, and shrub groupings are capped at 6 feet tall and 10 feet wide.
Violations & Fines
Failing to maintain the required fuel modification zone is a WUI Code violation; the fire district can order corrective work, and violators face a fine up to $1,000 or six months in jail, with each day a separate offense.
Frequently Asked Questions
How far does defensible space extend in unincorporated San Diego County?
Who is responsible for maintaining defensible space?
Sources & Official References
Other rules in San Diego County
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