Defensible Space Reference
Zone-based defensible space practice (CALFIRE / NFPA by name only).
Reference
Zones
- Zone 0 (0-5 ft from structure) Ember-resistant zone.Actions: No combustible mulch, no wooden fences directly attached, no firewood, no plants except low-growing irrigated groundcover.
- Zone 1 (5-30 ft) Lean, clean, and green.Actions: Mow grass; remove dead vegetation; space shrubs and trees; trim limbs 6 ft above ground; keep wood piles outside this zone.
- Zone 2 (30-100 ft) Reduced fuel zone.Actions: Thin trees so canopies do not touch; remove ladder fuels; mow tall grass; keep horizontal spacing between shrub clusters.
CALFIRE / NFPA published guidance by name only.
Checked against published worked examples from: CALFIRE / NFPA defensible-space published guidance (cited by name only).
Details, formula, and sources
Formula or table(reference page; no compute) Zone 0 / 1 / 2 wildland-urban-interface defensible-space actions per CALFIRE 2022 guidance and NFPA 1140 (Standard for Wildland Fire Protection, 2022), which absorbed NFPA 1144 (Reducing Structure Ignition Hazards from Wildland Fire).
Source and editionCALFIRE 2022 'Defensible Space' guidance by name; NFPA 1140 (formerly 1144) by name. IBHS Wildfire Prepared Home program by name.
Free accessCALFIRE guidance free at readyforwildfire.org. NFPA 1140: Free read-only access at nfpa.org/freeaccess. IBHS guides free at ibhs.org.
What governsEstimate. AHJ and licensed fire protection engineer govern.
API field namescitation