Towards the Development of a Comprehensive Lifecycle Risk Assessment Model for Green Roof Implementation

A green roof (GR) provides numerous social, environmental, and personal benefits through its lifespan, while exploiting these benefits is associated with several uncertainties. Since these risks to GR adoption have not yet been investigated and analyzed comprehensively, this research is aimed at developing an original risk assessment model to ensure the objectives of GR adoption are fully achieved. To this end, two novel approaches were employed, namely Monte Carlo-DEMATEL and fuzzy parsimonious analytic network process to determine the inner dependencies among the risk factors and rank them based on their relationships and importance, respectively. The findings showed that "irregular maintenance" and occurrence of "fire" are the most influential threats, while "flash flood reduction" and "achieving green building certificate award" are among the most influential opportunities. Moreover, it was shown that although "tax abatement" and "monetary loss" are the most important opportunity and threat, respectively, the ranking order of risk factors varies among an intensive GR and an extensive GR. Finally, it was concluded that with such analyses, the decision-makers have clear insights on the most influential positive and negative risks for managing purposes. The novel methods used in this research can be replicated to achieve more accurate and efficient results.