The American Society of Civil Engineers (ASCE) released the newly updated ASCE/SEI 7-22, Minimum Design Loads and Associated Criteria for Building Loads and Other Structures. This 2022 edition supersedes ASCE/SEI 7-16 and provides up-to-date and coordinated loading provisions for general structural design. This standard prescribes design loads for hazards such as tsunami, snow, rain, atmospheric ice (due to freezing rain), seismic, and wind as well as how to evaluate load combinations. It comes with the ASCE Hazard Tool, a quick and reliable tool to look up key design parameters specified in Standard ASCE 7. The hazard tool is the preferred data source for seismic, snow, and tsunami loads since paper maps for these hazards are no longer available; the tool also provides data for flood, rain, ice, wind, and tornado hazards. A user can enter the exact location of their site and obtain the relevant data for these hazards.
One of the new developments in SEI 7-22 is a chapter on tornado loads. Recent research on tornado climatology has shown that tornadoes occur with much greater frequency and intensity than has previously been understood. The 2011 Joplin Tornado created societal will to design for tornadoes. Be aware that under SEI 7-22, you cannot designate a building or other structure designed for tornado loads as a storm shelter. Storm shelter design must meet the additional critical requirements provided in the applicable building code and ICC 500.
Even if officials have not updated your governing building code to reference SEI 7-22, structural engineers should be aware of the changes and be cognizant that under certain circumstances, it may make sense to design to the latest standards to take into account available data and science on natural hazard loads for buildings. As always, it is important to work with both your client and the local authority having jurisdiction over the building to incorporate elements of SEI 7-22 not yet updated in your local building code.