|Investigation of building occupant fatalities and injuries, and overall destruction of the Joplin, Mo., built environment, compelled the NIST team to issue 16 recommendations for improving how buildings and shelters are designed, constructed, and maintained in tornado-prone regions.|
Protecting schools and their associated high-occupancy buildings from violent tornadoes is the goal of the first approved building code changes based on recommendations from the National Institute of Standards and Technology (NIST) technical investigation into the impacts of the May 2011 tornado that devestated Joplin, Mo.
Approved at a recent International Code Council meeting, the changes apply to the nation’s most tornado-prone regions. Enhanced protection will be required for new school buildings and additions to buildings on existing campuses, as well as facilities—gymnasium, theater, or community center—associated with schools where people regularly assemble. Under the updated codes, shelters must be provided that protect all occupants from storms with wind speeds of 250 mph, representing the maximum intensity category EF-5 on the Enhanced Fujita Scale. The area covered by the upgraded codes stretches from northern Texas to central Minnesota and western Oklahoma to western Pennsylvania. It includes the notorious “Tornado Alley” and “Dixie Alley” regions in the Midwest and South regions.
The improved storm shelter requirements will be published in ICC’s 2018 International Building Code and 2018 International Existing Building Code, each used as the basis for building, fire protection and life safety regulations promulgated and enforced by U.S. state and local jurisdictions. Based on findings from its Joplin study, NIST developed 16 recommendations for improving how buildings and shelters are designed, constructed and maintained in tornado-prone regions, along with improving the emergency communications that warn of imminent threat from tornadoes.
According to Joplin investigation team leader Marc Levitan, the IBC and IEBC changes mark the first milestone of the collaborative effort to implement the NIST recommendations. “Solid progress is being made working with code developers, state and local officials, the Federal Emergency Management Agency and others toward realizing all of the proposed improvements for tornado protection and resilience in our study,” he affirms.
Current efforts, Levitan adds, include developing: more detailed and accurate tornado hazard maps for the United States (to support standards on performance-based, tornado-resilient building designs); an improved Fujita scale based on advanced techniques for wind speed estimation; draft standards for better selecting buildings to serve as disaster shelters; and, guidelines for determining the best available tornado refuge areas in existing buildings.
NIST’s Joplin investigation team members also recently provided their expertise and insight to help FEMA improve guidance on public sheltering strategies and practices in its publication, FEMA P-361, Safe Rooms for Tornadoes and Hurricanes: Guidance for Community and Residential Safe Rooms, Third Edition. Levitan and his colleagues will continue to work with partners to realize the main goal of the Joplin investigation: nationally accepted standards for building design and construction, public shelters and emergency communications that can significantly reduce deaths and the steep economic costs of property damage caused by tornadoes.