The American Society of Civil Engineers released a new update to their most widely used standard today, ASCE/SEI 7-22 Minimum Design Loads and Associated Criteria for Building and Other Structures. As the increasing frequency of severe storms puts strain on communities across the globe, the design standard’s new flood load provisions will protect against 500-year flood events, which is a significant improvement to the 100-year flood hazard referenced in the previous version. The update, which is available in a supplement as a free download, is a significant revision of the design provisions in Chapter 5 to strengthen building resilience against the flood hazard. The ASCE 7 national loading standard is an integral part of building codes in the United States and around the globe.
The primary technical updates relative to climate impacts include a new requirement tying flood hazard mitigation design to Risk Category, which is consistent with other environmental hazards in ASCE 7. There are four categories from which a building designer can select based on the intended use of the structure, ranging from the least risk to human life in the event of failure in Risk Category I structures to the greatest risk to human life in the event of failure in Risk Category IV structures. The new provisions require Risk Category II structures and above to use the 500-year floodplain to determine flood loads. Risk Category II structures, the most commonly used category, include one- and two-family buildings, low to medium occupancy businesses, or recreational facilities. Risk Category I structures, including agricultural buildings such as barns and sheds, could still follow 100-year flood provisions.
The supplement also introduces a new requirement for relative sea level change as it relates to each individual structure. The sea level rise estimated over the service life of the structure must be added to the design’s flood mitigation plans.
Visit https://ascelibrary.org/doi/10.1061/9780784415788.sup2 to download the supplement.
