Feasibility of green roofs in the mediterranean region: A stochastic study using a Monte-Carlo financial model

Green roofs, also known as vegetated roofs or living roofs, have gained increasing attention in recent years due to their potential to address various environmental challenges in urban areas. These innovative roofing systems offer a promising solution to mitigate urban heat island effects, manage stormwater runoff, reduce energy consumption, improve air quality, enhance biodiversity, and contribute to cities' sustainability and liveability. This paper presents a comprehensive analysis of the feasibility and sustainability of green roofs in the Mediterranean zone, with an Italian location as a case study. The analysis considers intensive or extensive green roofs, applicable tax incentives, and different cost/benefit considerations. A probabilistic study of the financial model was performed using a Monte-Carlo based method. The results show that green roofs provide private and social benefits and are financially feasible. Critical factors for increasing sustainability and financial feasibility are increment of energy saving potential, long lifetime, and reduction of maintenance. The payback period is sensitive to scenarios where all the benefits become applicable, with regulatory incentives and tax reductions. Policymakers should encourage the application of green roof technology in new buildings and retrofitting old ones.