A Defensible space is an area where material capable of causing a fire to spread has been treated, cleared, reduced, or changed to act as a barrier between an advancing wildland fire and resources or lives at risk. In practice, defensible space is generally defined as an area of 30 feet or more around a structure that is cleared of flammable brush or vegetation or other fuels. It also reduces the chance of a structure fire moving from the building to the surrounding wildlands and provides room for firefighters to do their jobs.