Tornadoes are among the most destructive natural disasters, posing significant risks to communities and infrastructure, underlining the need for robust methodologies to assess building vulnerability and enhance structural resilience. This research addresses the gap in current tornado vulnerability studies by investigating the impact of material deterioration on building fragility, focusing on commercial and government buildings at the end of their useful life. The overarching goal is to comprehensively quantify the effects of material deterioration on tornado vulnerability, including its implications for EF-scale ranking and associated wind-speed thresholds for Damage Indicators (DIs) and Degree of Damage (DOD) classifications.As a secondary goal, the research seeks to understand the critical components prioritized during condition assessments to facilitate comparisons with National Weather Service (NWS) post-event storm surveys.The research employs a multifaceted methodology to achieve its objectives. Firstly, a Qualtrics survey of architects, engineers, facility managers, construction managers, and building owners reveals critical components prioritized during facility condition assessments of commercial and government buildings, facilitating comparisons with post-event storm surveys. The analysis shows that while built environment professionals often focus on operational and maintenance concerns, NWS post-event storm surveys prioritize structural integrity and safety. This misalignment underscores the importance of harmonizing pre- and post-event storm surveys. Secondly, predictive models are developed to forecast deterioration trends for various building components, such as roofs, walls, doors, and windows. These models provide valuable insights into the dynamics of material degradation over time, leading to the analysis of deterioration rates under different maintenance scenarios, ranging from poor to excellent practices. Focusing on deterioration rates for poorly maintained buildings at the end of their useful life and using probabilistic modeling approaches, the research develops time-dependent deterioration fragility curves to quantify the changing vulnerability of materials used in commercial and government buildings over time. The results reveal decreased wind speed thresholds for EF-scale ranking, indicating notable changes in tornado-induced damage potential due to material deterioration. These findings highlight the importance of considering time-dependent deterioration fragilities in tornado vulnerability assessments and the observed leftward shifts in fragility curves. Additionally, changes in EF-scale ranking and DOD wind speed thresholds underscore the probable inadequacy of existing evaluation protocols that do not account for material deterioration. Post-event storm surveys may now consider the impact of aging and degradation on building resilience to assess structural integrity and accurately prioritize repair and reconstruction efforts.This research enhances resilience and promotes sustainable development in tornado-prone regions by illuminating the dynamic nature of tornado vulnerability.