Identifying influential factors in end-of-life decision-making for buildings using the Delphi method

The end-of-life (EOL) of buildings presents a critical decision point for owners, influencing environmental, economic, and resource outcomes. Traditionally, demolition has been the dominant EOL strategy, often driven by economic factors. However, prioritizing demolition without considering alternatives, such as preservation, or deconstruction, results in increased waste, and missed economic opportunities. Approximately 90% of the Architecture, Construction, and Engineering (AEC) industry-generated waste originates from this phase, where conventional demolition overlooks the residual value of materials. However, a comprehensive hierarchy of EOL strategies can enhance resource conservation and provide owners financial benefits, but effectively implementing these strategies requires a deeper understanding of the considerations surrounding EOL decision-making. While existing literature explores individual strategies, it does not consider the full range of EOL options available to stakeholders. Using a mixed-method approach, including content analysis and the Delphi method, this research identifies and rates these factors when considering all possible strategies, within the three pillars of sustainability: environmental, social, and economic. Our findings highlight environmental factors, including the property owner's awareness of environmental issues and their intention to reduce energy consumption and carbon footprint; social factors like regulatory compliance and safety considerations; and economic factors including financial capability, incentives for salvaged materials, labor costs, storage, and the comparative value of salvaged versus new materials as the most influential factors. The research also indicates that some factors emphasized in literature were not considered influential by stakeholders, suggesting a misalignment between scholarly assumptions and practical decision-making. This research contributes to the body of knowledge by systematically identifying and empirically validating the most influential factors shaping EOL decision-making. It highlights novel factors not previously reported in the literature, providing insights into why materials with reuse potential are often discarded. These findings function as a foundation for developing integrated EOL management strategies, guiding future research, policy, and industry practice.