Origins of the Wildfire Code
Wildfires are unavoidable in Boulder County and the Western US. The Black Tiger Fire swept through the foothills of Boulder County, Colorado in 1989, destroying 44 homes and other structures and causing an estimated $10 million in damage. The fire highlighted the need for ignition resistant building codes in the county.
The conditions that principally determine whether a home survives a wildfire occur within 100 feet of the structure. This includes the home’s exterior materials, the surrounding landscaping and vegetation, and the agglomeration of urban and wildland fuels in this area. Boulder County’s Land Use and Building Code addresses these elements in order to reduce the risk of loss of life and property.
Initial measures to address wildfire resiliency through the building and land use code were adopted in 1993 and applied to construction in the western part of the county, designated Wildfire Zone 1. At the time, only this area was deemed at high risk from wildfires. The wildfire mitigation code requires the use of ignition resistant and noncombustible materials in home construction and limits the amount of flammable vegetation that can be allowed to grow near homes. These codes have been based on wildfire science findings from the US Forest Service Missoula Fire Science Laboratory, National Institute of Standards (NIST), Insurance Institute for Business & Home Safety (IBHS), National Fire Protection Association (NFPA), Cal-Fire and the University of California at Berkeley, and sections of the IWUI (International Wildland Urban Interface) Code. The county’s wildfire code requirements have been updated periodically as new science and standards become available.
The eastern part of the county had few notable fire events until the Marshall Fire in 2022. That fire destroyed almost 1,100 homes including over 150 homes in unincorporated Boulder County and over 900 in adjacent Superior and Louisville. This prompted the county to update its building code to include ignition resistant requirements for Wildfire Zone 2 as well, effective June 2022. The codes are a vital part of the county’s wildfire mitigation efforts, and they will continue to play an important role in reducing the risk of loss of life and property from wildfires.