Sustainable Green Roofs: Thermal Insulation & Environmental Assessment

Abstract

The rapid urbanization and uncontrolled land-use change in cities have identified environmental challenges which include Urban Heat Island (UHI) effect, ecological degradation, and increased climate-related risks. Within this context, green roofs have emerged as multifunctional solutions with the potential to enhance thermal comfort, improve energy performance, and strengthen urban resilience. While international studies have demonstrated their technical and environmental benefits, the success of green roof integration is also contingent upon public acceptance, regulatory support, and affordability, particularly in developing regions. This research advances discourse by combining socio-perceptual analysis with technical performance assessment. First, the study evaluates residents’ perceptions and willingness toward green roof adoption, focusing on factors such as environmental awareness, regulatory provision, and the role of subsidies or financial incentives. Second, a simulation-based comparison of thermal and energy was executed using a case study building, located in Timisoara, Romania, a five-storey building with an extensive green roof, representing the awareness. The building model was analyzed through dynamic simulations to compare conventional roofing with extensive green roofs combined with 5 insulation materials, including glass wool. Foamed glass, rock wool, expanded polystyrene (EPS), and polyurethane. The findings show that polyurethane insulation, when integrated with green roofs, delivers superior performance, reducing summer indoor air temperatures by approximately 1°C and lowering the U-value by 0.08 W/m². K, and achieving up to 33% reductions in carbon emissions along notable energy savings. At the same time, the socio-perceptual dimension shows that adoption willingness is shaped by awareness of benefits, economic feasibility, and enabling regulatory frameworks.