Wildfire Zones: Irvine vs Mission Viejo
How do wildfire zones rules compare between Irvine, CA and Mission Viejo, CA?
Irvine has fewer restrictions than Mission Viejo.
Irvine, CA
Orange County
Irvine adopted updated Fire Hazard Severity Zone maps in 2025, expanding Moderate, High, and Very High designations into multiple communities. Properties in FHSZ areas face enhanced building standards and defensible space requirements.
View full Irvine rules →Mission Viejo, CA
Orange County
Portions of Mission Viejo along the eastern and southern hillside edges are designated as Very High Fire Hazard Severity Zones by CAL FIRE and OCFA. Properties in these zones must maintain 100 feet of defensible space, use fire-resistant building materials, and comply with OCFA vegetation management inspection programs. Annual brush clearance is required before fire season.
View full Mission Viejo rules →Key Facts Comparison
| Fact | Irvine | Mission Viejo |
|---|---|---|
| FHSZ Map | Updated 2025, effective July 2025 | - |
| Zones | Moderate, High, Very High | - |
| Expanded Areas | 8+ communities added | - |
| Building Code | CBC Chapter 7A in VHFHSZ | - |
| Defensible Space | 100 ft required in FHSZ | 100 feet required from structures |
| Zone 1 Clearance | - | 0–30 feet, remove all combustibles |
| Inspections | - | Annual OCFA vegetation management checks |
| Building Materials | - | Class A roof, fire-resistant per CBC Ch. 7A |
| Inspection Period | - | April through June annually |
Highlighted rows indicate differences between cities.
Irvine FAQ
Is my Irvine home in a wildfire zone?
Check the city's Fire Hazard Severity Zone Map. The 2025 update expanded zones into Orchard Hills, Woodbury, Portola Springs, Quail Hill, Turtle Rock, and other communities.
What building requirements apply in fire zones?
Properties in Very High FHSZ must meet CBC Chapter 7A standards for ignition-resistant construction, including Class A roofing and fire-resistant walls.
Mission Viejo FAQ
Is my Mission Viejo property in a wildfire hazard zone?
Properties along the eastern hillsides near Trabuco Canyon and areas near Oso Parkway may be in a Very High Fire Hazard Severity Zone. Check the CAL FIRE hazard severity zone map or contact OCFA Community Risk Reduction at (714) 573-6000 for your specific address.
What does defensible space clearance require?
Within 30 feet of your home, remove all dead vegetation, dry leaves, and combustible materials. From 30 to 100 feet, reduce and space vegetation to slow fire spread. Trees should be limbed up 6 feet from the ground and spaced so canopies do not touch.
When does OCFA inspect for brush clearance?
OCFA typically conducts vegetation management inspections from April through June. Property owners in designated zones receive written notices with a compliance deadline. Contact OCFA at (714) 573-6000 if you have questions about your inspection schedule.
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