Risk identification and assessment of passive roofs for rural housing in hot and dry regions using Delphi method

BACKGROUND AND OBJECTIVES: Passive roofs are increasingly recognized as effective solutions for improving thermal performance and reducing energy consumption in buildings. Nevertheless, the execution of these measures in rural housing sectors is frequently compromised by a complex array of uncertainties, including those related to policy management, financial constraints, environmental factors, health and safety, and quality control. Existing studies mainly focus on roof performance and energy benefits, while systematic risk assessment remains limited, particularly in rural areas with constrained resources and technical capacity. The study objectives were to develop a structured framework to identify and assess the risks associated with passive roofs in the hot–dry regions of Southwest China.METHODS: A two-round Delphi survey was conducted to evaluate impact and frequency, and consensus was tested using Kendall’s W and interquartile range. Risk levels were subsequently evaluated through the application of a modified risk matrix featuring ۰.۸-interval classification..FINDINGS: A total of ۴۹ preliminary risk factors were identified through literature review and expert judgment. After screening using the content validity ratio, ۴۷, ۳۵, ۴۸, and ۴۲ risk factors were retained for blue roofs, cool roofs, green roofs, and ventilated roofs, respectively. The findings demonstrate that the highest cumulative risk levels are associated with green and blue roofing systems. Blue roofs contain ۱۵ high-risk and ۵ very high-risk factors, while green roofs contain ۱۶ high-risk and ۵ very high-risk factors. Cool roofing alternatives presents fewer extreme vulnerabilities but conversely generate the highest percentage of high-risk outcomes. Ventilated roofs show relatively lower overall risk levels, although several critical risks remain. Across all roof types, high-risk factors were primarily associated with construction quality, management capacity, maintenance requirements, and economic constraints. several low-consensus risks were observed, reflecting the site-specific constraints governing passive roofing systems in rural jurisdictions.CONCLUSION: The findings indicate that risk levels are strongly associated with roof complexity, construction conditions, and maintenance requirements. This framework delivers a systematic basis to guide risk-informed decisions regarding rural passive roofing installations.