What is the Home Ignition Zone?

By Katherine Sears, community preparedness & fire prevention specialist at the DNRC Northeastern Land Office, Lewistown

June 2025

With recent news of devastating wildfires across the nation, it’s easy to feel powerless about the threat of a wildfire destroying your home or threatening your family. While some wildfire risk factors are outside your control, there is still a lot you can do to protect your home and property. 

In fact, the condition of your home and the surrounding vegetation has the biggest influence on whether a home will ignite from a wildfire. The home itself and area around it is referred to as the Home Ignition Zone (HIZ).  

To understand why the HIZ is so important, let’s talk about how homes ignite. 

Are you picturing a huge flame front consuming a home? The reality is, while direct flame contact can ignite homes, the most common source of ignition is embers. It is estimated that embers are responsible for over 90% of homes destroyed by wildfire.  

During wildfires, small embers can travel miles ahead of the flame front, carried by wind. These tiny, burning particles can easily accumulate in areas where leaves and debris naturally pile up around your home, resulting in ignition.  

Radiant heat from a fire is another common source of home ignition. Radiant heat can ignite or preheat surrounding combustible materials, making them more susceptible to ignition. This is more likely when there are structures close together.  

By focusing on the HIZ, residents can mitigate the risk of property loss due to wildfires. The HIZ is broken up into three different areas: 0-5 feet, 5-30 feet, and 30-100 feet, each with specific recommendations for reducing wildfire risk.  

Immediate Zone: 0-5 feet 

Take a few steps out your front door and look back at your house. Do you notice anything flammable such as mulch or dried leaves? If so, consider removing or replacing these materials with non-flammable options like rocks.  

The immediate zone is the most important piece to mitigating wildfire risk. Keeping your home  in good condition is equally important. Regularly inspect siding, roofing, and vents. Vents should be screened with at least 1/8” non-flammable mesh to prevent embers from entering the home.  

Intermediate Zone: 5-30 feet 

In this zone, your goal is to create and maintain defensible space. Properly maintained landscaping can reduce fire spread and intensity.  Vegetation should have ample spacing, and removing ladder fuels – anything that can carry a flame from the ground up into the canopy a tree –  should be considered as well.  

This is also a good place to add fuel breaks, such as stone walkways, gravel paths, or a driveway to interrupt fire. 

Extended Zone: 30-100 feet 

In this outermost zone, the goal is to reduce wildfire intensity as it approaches your home.  You’ll want to continue healthy spacing of trees and shrubs, breaking up continuous fuels, to keep fire close to the ground where it's easier to extinguish. Remove ladder fuels and thin vegetation as needed.   

A helpful way to visualize this is to imagine a wildfire approaching your property from a distance. Is fire behavior decreasing and staying on the ground? If you think the fire will move quickly into the treetops, consider making some changes.  

While this may seem overwhelming, it’s easiest to start with the 0-5 feet zone right around your home. Get that tidied up and move on to the next project.  

As the snow melts and you begin your yard work, keep the HIZ in mind. You’ll be surprised at the little things you can do to mitigate your wildfire risk.   

For more information on the Home Ignition Zone, visit MTFireInfo.org.