Updates to the Design of Buildings for NBCC 2025 for Climate Adaptation, Resilience, and Associated Initial Cost Impact

Most building codes have assumed stationary historical climatic data that can be statistically extrapolated to the future. However, nonstationarity has been shown in projections of future climatic data relevant to the design of buildings. For climate adaptation and resilience for Canadian buildings, recent studies proposed methods to integrate future climates into determining the climatic design loads and transitioning from the uniform hazard design approach to the uniform risk design approach in the National Building Code of Canada (NBCC). This study summarized these proposed changes to NBCC and derived the corresponding design scenarios for buildings in 17 cities across Canada. Three prototype building geometries with various construction materials and design schemes were developed to assess the impacts of the proposed changes on the climatic design loads and associated costs. The results showed that the proposed code updates incorporating climate change impact can increase or decrease the climatic design loads geographically. The associated cost impact on the structural design is minimal and mostly within the range that engineering design can accommodate with small to negligible initial cost increases.