Community Wildfire Mitigation

Defensible space is an area around a structure where fuels and vegetation are treated, cleared or reduced to slow the spread of wildfire towards the structure.

Defensible space provides room for firefighters to effectively and safely defend a structure and reduces the chance of a structure fire moving from the building to the surrounding vegetation.

Reducing fuel loads and vegetation around a home greatly improves the survivability of a structure during a wildfire. Be sure to provide clearance and choose appropriate fire-resistant plantings.

Keep the fuels and vegetation area 30 to 50 feet immediately around a home or structure treated, cleared or reduced to slow the spread of wildfire. Drought tolerant and fire resistive plants are the best choices for this area. If you think your property contains rare, threatened or endangered species or sensitive habitat, contact the City’s Planning Division at 760-744-1050, ext. 3237. 

Within the remaining 70 to 150 feet* of defensible space, plants should be horizontally and vertically spaced, and native vegetation should be thinned. Lower tree branches at least six feet from the ground should be removed.

(*Minimum of 100 feet from structures built prior to January 1, 2004 and 150 feet for those built after.)

• Decks, patios and fences: Limit combustible structures attached to your residence – such as decks, patios and fences.
• Wood piles: Keep combustible debris such as stacked wood piles away from your home’s walls.
• Dead leaves: Remove dead leaves and other debris from under solar panels, eaves and gutters.
• Tree branches: Dead tree branches hanging over a roof should be cut back. 

• Address visibility: Make sure your home address is posted on a highly contrasting background and clearly visible from the street, especially at night.
• Clear vegetation: Clear flammable vegetation to at least 10 feet from roads and cut back overhanging tree branches.
• Turnarounds: Keep turnarounds on dead-end roads and long driveways clear for emergency vehicles. 

• Evacuation plan: Your plan should include escape routes out of the wildfire area and a meeting place.
• Exit routes: Identify at least two exit routes from your home and neighborhood.
• Consideration: Should be given to pets, important documents, medication, and irreplaceable items.

• 9-1-1: If you see fire or smell smoke, your first line of defense is calling 9-1-1.
• REVERSE 9-1-1: Register your cell phone for Reverse 9-1-1 emergency calls via Alert San Diego by visiting www.AlertSanDiego.org.

• Roof: Roof or re-roof using non-combustible materials such as composition, metal or tile.
• Vents: Ensure vents are ember-resistive to prevent the intrusion of flying embers.
• Eaves and soffits: Ensure eaves and soffits (arches, overhangs and balconies) are protected with non-combustible materials.
• Windows: Windows should be dual-paned with one pane of tempered glass to reduce the chance of breaking during a fire.
• Walls: Walls should be built with ignition-resistant materials such as stucco, fiber cement, stone veneer or fire-retardant treated wood.
• Decks: Ensure decks within 10 feet of a building are built with ignition-resistant or non-combustible materials.

Residents should register all cell phones with AlertSanDiego, to receive emergency notifications.

During an emergency, residents should stay updated on the latest local safety information by visiting the City’s website; following the City on Facebook, Twitter and Instagram with the handle @sanmarcoscity; registering for e-notifications; and turning radios to AM 1610.

What is Zone 0?

Zone 0 is the area within 0–5 feet of your home or structure. It is the most critical zone for wildfire protection because it is where homes are most likely to ignite.

Wildfires often spread through wind-driven embers, which can travel long distances and ignite materials near buildings. Creating a fire-resistant Zone 0 helps stop those embers from turning into structure fires.

Zone 0 requirements (0-5 Feet)

To create an ember-resistant space, the area immediately around your home should be clear of anything that can burn.

Remove:

• Dry leaves, pine needles, and debris
• Wood mulch and bark
• Dead plants, grass, and shrubs
• Firewood stacks and outdoor storage
• Flammable outdoor furniture or décor

Avoid:

• Combustible fencing attached to the home
• Vegetation directly against structures
• Any material that can easily ignite from embers

What you can use instead: 

Replace flammable materials with non-combustible alternatives, such as:

• Gravel or decomposed granite
• Concrete or pavers
• Stone or rock landscaping
• Metal or fire-resistant materials

These materials create a protective barrier that helps prevent ignition.

Ongoing maintenance

Zone 0 is not a one-time project—it requires regular upkeep:

• Clear debris from roofs, gutters, and around the home
• Keep the area clean and free of buildup
• Inspect regularly, especially during fire season

Upcoming requirements (California)

California is moving toward stricter enforcement of Zone 0 under state law. These rules are designed to:

• Improve wildfire resilience
• Reduce structure ignition risk
• Standardize safety practices in high fire hazard areas
  
  

Homeowners in high-risk zones may be required to comply in the near future.

Key takeaway

The first five feet around your home can determine whether it survives a wildfire.

By removing combustible materials and maintaining a clean, fire-resistant space, you create your strongest line of defense.