Lifecycle Benefit–Cost Analysis of Wood-Frame Residential Buildings in Tornado-Prone Regions of the US

Abstract Tornadoes pose a significant threat to residential buildings in the United States, often resulting in extensive damage and loss of life. Despite their destructive potential, most residential building codes currently lack specific requirements for tornado-resistant design, leaving many structures at risk. This study presents a risk-based lifecycle benefit–cost analysis (BCA) framework to assess the economic justification of incorporating up to EF-2 tornado-resistant design measures into wood-frame residential buildings across tornado-prone regions of the US. The analysis integrates probabilistic tornado hazard models with building fragility functions to assess the performance of two design alternatives: a minimum-standard building and an EF-2 tornado-resistant building. A representative one-story, single-family, wood-frame structure is used as the archetype. The lifecycle cost model accounts for both direct and indirect losses, including casualties, relocation, and debris removal. A Monte Carlo simulation is utilized to quantify uncertainty in the estimation of lifecycle costs and benefit–cost ratios. Results show that EF-2 tornado-resistant construction is highly cost-effective in high-risk regions, with benefit–cost ratios reaching up to 13 to 1 over a 50-year service life. The payback period for these mitigation measures ranges from 2 to 3 years in high-risk areas to over 20 years in lower-risk zones. These findings provide strong evidence for expanding the adoption of tornado-resistant construction standards in residential buildings, particularly in tornado-prone areas, to mitigate damage, reduce losses, and improve safety.