Snow load design changes in ASCE/SEI 7-22

The latest ASCE/SEI 7-22 Minimum Design Loads and Associated Criteria for Buildings and Other Structures standard contains some notable changes.

“Structural engineers should be aware of significant changes in the 2024 IBC Chapter 16 and ASCE 7-22 for snow loads,” according to an article at Structure magazine. “Snow loads are now based on the risk category of the structure and use strength-based design values.” The new standard includes new strength-based ground snow load (GSL) maps based on the risk category of a building. The new maps are also used in the 2024 International Building Code (IBC).

The introduction of strength-based GSL values has led to modifications in the load combinations. For allowable stress design (ASD), the snow load adjustment factor converts ground snow load to flat roof snow load with a 0.7 exposure reduction factor.

“This should not be confused with the ASD modification. ASCE 7-22 Section 7.3.3, Minimum Snow Load for Low-Slope Roofs, further requires a minimum snow load independent of additional adjustments,” the article says. “Application of the adjustment factors is critical for the new snow load design provisions.”