Defensible Space

According to the Colorado State Forest Service, "Defensible Space" refers to the area around a home or other structure that has been modified to reduce fire hazards. In this area, natural and manmade fuels are treated, cleared or reduced to slow the spread of wildfire. Defensible space reduces the likelihood of a structure igniting by direct contact with flame or by exposure to the radiant heat of a fire, and helps limit the production of embers that can spread the fire to neighboring homes and vegetation.

Creating defensible space involves establishing series of management zones around a building or other structure, also referred to as Home or Structure Ignition Zones (HIZ or SIZ).

The three defensible space zones are defined by their distance away from a structure:

• Zone 1 (0 to 5 feet): Immediate Zone
  • The area nearest the home and other structures. It requires the most vigilant work to reduce wildfire hazards.
• Zone 2 (5 to 30 feet): Intermediate Zone
  • The area transitioning away from the home, where fuels should be reduced to slow down an approaching fire.
• Zone 3 (30 to 100 feet): Expanded Zone
  • The area farthest from the home. It extends to 100 feet from the home on relatively flat ground.

The specific Site and Area Requirements can be found in Chapter 5 of the Colorado Wildfire Resiliency Code.