Building Code

The International Codes provide safeguards and ensure uniformity in the construction industry. One or more of these International Codes becomes the law of a particular state or jurisdiction when formally adopted (and often amended)by the appropriate state or local governmental authority.

Statewide building codes—and adequate enforcement of codes—play a vital role in public safety and loss prevention. They can reduce the need for public disaster aid and increase a community’s resilience. While the state does not have a mandatory code, most local governments in Colorado have adopted all or most of the International Codes listed above. If a county or municipality does not have a building code, factory-built structures and buildings constructed on site intended for multiple occupancy are subject to building standards set forth by the state Division of Housing. According to the Natural Hazard Mitigation Saves: 2017 Interim Report, released by the National Institute of Building Sciences, implementing mitigation measures in new construction to exceed select provisions in the 2015 IBC and the 2015 IRC and the implementation of the WUI Code saves society an average of $4 for every $1 spent on mitigation.

If a county has enacted a building code, it is also required to adopt and enforce a building energy code that meets or exceeds the standards in the 2003 International Energy Conservation Code (IECC). The relatively new International Green Construction Code (IGCC) was released by the ICC in 2010 and was created to aid in the construction of sustainable buildings in the business and residential sectors.

In addition to the IGCC, there are other International Codes designed to address specific hazards such as the Wildland-Urban Interface Code (IWUIC or WUI Code). See separate tool profile on the WUI Code.

Larimer County adopted its first building code in 1972, and continues to adopt the most current editions of the International Building Code with local amendments. A recent amendment to the code requires wildfire hazard mitigation standards for new construction. This section establishes minimum standards for the design and construction of new or substantially improved buildings in wildfire hazard areas for the protection of life and property. Requirements include specifications for fire-resistant construction practices in addition to the provision and maintenance of defensible space in compliance with the guidelines prescribed by the Colorado State Forest Service. They also address standards for liquid propane gas facilities, containers, and tanks and requirements for the installation of spark arrestors for chimneys. These amendments apply to all locations within the wildfire hazard area as defined in the Larimer County Wildfire Mitigation Area Map. They are enforced by the Building Official who has the authority to approve alternate materials and methods of compliance not specifically prescribed by the code so long as they are equivalent in terms of suitability, effectiveness, fire resistance, durability, and safety. These code amendments are a critical component to the County’s broader Wildfire Safety Program (Building, n.d.a.).

Boulder, Larimer, and Weld Counties (Flood Mitigation). While most communities in Colorado have adopted building codes based on international standards that include minimum flood-resistant design standards, the State of Colorado requires each to adopt an amendment to these provisions in compliance with its own “Rules and Regulations For Regulatory Floodplains In Colorado” (2011) as established by the Colorado Water Conservation Board (CWCB). These rules include higher regulatory standards that exceed most codes and minimum standards of the National Flood Insurance Program (NFIP), and communities have the option to adopt even higher standards through their own local ordinances and building code amendment process.

One common approach to higher regulatory standards is the adoption of freeboard: an additional margin of safety expressed in feet above a predicted water surface elevation, typically defined as the Base Flood Elevation (BFE) on a FEMA Flood Insurance Rate Map (FIRM). In 2011 CWCB amended its rules to require one foot of freeboard for all new or substantially changed structures in floodplains. A number of communities in Colorado had already amended their local building codes and relevant ordinances to meet or exceed this standard, and the risk reduction benefits of doing so were realized following the September 2013 floods. For example, most communities in the hard hit counties of Boulder, Larimer, and Weld had amended their codes to include a freeboard requirement – and many include a two foot freeboard. A 2015 FEMA study determined that $183 million in losses were avoided in these three counties during the 2013 flood event through these more stringent regulatory practices (Reducing Losses, 2015).