Home Ignition Zones (HIZ)

In Colorado, wildfires are not a "what if" but a "when". To protect your lives and property from the devastating effects of wildfire, take into consideration your Home Ignition Zones (HIZ). The two primary determinates of a structures ability to survive a wildfire are ignitability and defensible space. Often, homeowners think that wildfire mitigation requires clearing all vegetation, but HIZ’s are a proven approach for reducing risk and protecting lives and property. The HIZ's help you assess the space around your home by setting three primary zones which are generally explained below. For more information about HIZ, please visit the Colorado State Forest Service HIZ Guide here. Click here for the HIZ Guide in Spanish. To get in depth information about your property sign up for a free Home Risk Site Visit here and learn about WAP’s Defensible Space Cost Share Program which assists homeowners in creating defensible space.

 

Zone 1 (0-5 feet)

Since this is the closest to your home, it requires the most vigilance to remove flammable materials such as firewood, brush, pine needles, or tree branches. Keeping 5 feet around your home clear can help protect your home from ignition through embers. Use nonflammable, hard surface materials in this zone such as rock, gravel, cement, brick, or bare earth.

Next Steps:

  • clear gutters of debris

  • do not store flammable materials under deck

  • No mulch within 5 feet

  • Screen chimney or spark arrestor

  • 1/8” metal mesh screen on vents

  • No pine needles, leaves, debris on roof or decks

  • Firewood stored at least 30 feet away

  • Limb branches 10' from structure and 6-10’ from ground

  • Other home Hardening

    • Class A fire resistant roof (metal, composite shingles, etc.)

    • Fire retardant siding (stucco, siding, rock, etc)

    • Multi-pane, tempered glass, or glass block windows

 
 

Zone 2 (5-30 feet)

Zone 2 is meant to minimize a fire's intensity and its ability to spread by giving the fire less fuel. A few ways to do this is to reduce large accumulations of surface fuels such as branches or slash, create small tree groupings with at least 30' between groupings or 15' between individual tree crowns, and remove ladder fuels.

Next Steps:

  • create 15’ clearance between tree crowns (steep slopes should increase this number)

  • Limb trees 10’ from ground and clear all shurbs under trees

  • Remove dead and dying trees

  • Shrubs are at least 10’ away from tree branches

  • Branches, slash, and chips are no more than 4” deep

  • grasses mowed to 4” or less

  • While small groups or clumps of trees are acceptable, clearance around crows should increase to 30’

  • Remove common ground junipers as they are highly flammable and tend to hold a layer of flammable material beneath them.

 

Zone 3 (30-100 Feet)

Zone 3 aims to keep fires on the ground and improve forest health. A healthy forest includes trees of different ages, sizes, and species. Reducing ladder fuels and increasing space between tree crowns helps fires move to the ground to reduce the intensity of the fire. If Zone 3 moves beyond your property, we encourage you to reach out to adjoining property owners to complete defensible space.

Next Steps

  • 10’ clearance between tree crowns

  • thin shrubs, especially those under trees acting as ladder fuels

  • 30’ crown clearance between clumps of trees

  • remove dead, dying, or diseased trees

  • consider creating openings or meadows between clumps of trees

 

We encourage all homeowners in the 5-county region to have a free Wildfire Risk Site Assessment (Site Visit). At the Site Visit, a County Coordinator will survey your property with you and give you site-specific recommendations. If you are interested in utilizing one of WAP’s many incentive programs, the Coordinator can offer you instructions to move forward at that time.