Impact of building code changes on future hurricane risk of residential buildings in changing climate

Abstract

Hurricanes are one of the biggest natural hazards to residential buildings under the worsening climate change. As the effect of climate change on hurricane risks has been suggested by many studies, the urge to change building codes due to climate change has been rising. ASCE issued the COP26 communique at the 2021 United Nations Climate Change Conference, suggesting building code change as one way to adapt to climate change and encourage resilient and sustainable infrastructure. Many studies suggest increasing design wind speed in building codes. Others suggest new or changed load factors to account for the influence of climate change. While it is essential to implement climate-conscious building codes to properly manage hurricane risks, the corresponding structural risk mitigation strategies and their risk mitigation benefits are yet to be investigated fully. Furthermore, building codes donﾒt reach existing buildings that are most vulnerable and take up the majority of the building inventory. Therefore, hurricane risk mitigation efforts should be expanded to existing buildings to effectively protect residential buildings from hurricane damage.

This study investigates the effect of installing essential structural components (accordion windows, perforated parapets, and hurricane clips) which have hurricane risk mitigation characteristics to study to what extent they can reduce the hurricane losses to 8 southeastern states in the US. From the investigation, it is found that the new building prototypes with the three additive structural components can effectively decrease the average hurricane loss ratios over all the studied counties under current, short-term (2020-2030), and long-term (2090-2100) RCP 8,5 climate conditions. When only building code change is considered, the average loss reduction ranges from 12% to 15% among the three climate scenarios, while the reduction rate would double if five percent of the maintenance rate is assumed. Furthermore, the number of counties that benefit from the new building code increases as a more severe climate condition is considered. This study also discovers that the areas with the highest hurricane risks, i.e., most of the counties in Florida, would benefit the most from the new building prototypes with hurricane damage mitigation characteristics in all three climate scenarios. The maximum regional average reduction reaches 29.65% in Florida under the short-term (2020-2030) climate condition.