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Green roofs are a fundamental technology in the transformation of urban centers into more sustainable environments, with a positive impact on buildings, cities, and their inhabitants. Yet, green roof technology may require the use of materials with a high environmental impact, namely, when associated with large transport distances. The present work arises from the need to find an environmental solution to use in an eco-school on one of the Azores islands. It tests green roofs on a wooden structure using local and sustainable materials. Prototypes were built to monitor their performance and to complement the theoretical information investigated regarding the construction systems of green roofs with alternative materials. The installation of the prototypes was accompanied by the school community, and the performance was monitored. The pumice stone proved to be an efficient solution for the drainage layer of the green roof. The use of local soil (volcanic origin) instead of a commercial substrate proved to work properly, both for drainage and for vegetation growth. Finally, the results also contribute to a better understanding of green roofs on wooden structures and encourage the use of local materials in future projects, with a view towards a circular economy. [ABSTRACT FROM AUTHOR]

Several studies have assessed the thermal performance of green and cool roofs. However, few have comprehensively addressed Brazilian buildings and climates, considering indoor and outdoor environments. Considering three Brazilian cities, this study aims to assess the performance of green and cool roofs compared with traditional fibre cement roofs in a typical multifamily residential building. Energy consumption, thermal comfort, and outside surface temperature were assessed using computer simulation. The results show that the cool roofs performed better in cities with warmer climates (e.g., Cfa and Aw), reducing electricity consumption by up to 24.8% compared with traditional roofs. Green roofs are better suited for colder climates (e.g., Cfb), with up to 28.2% energy savings. Green roofs provided the highest percentage of thermal comfort hours in all climates. Cool and green roofs provided hourly reductions in outside roof surface temperature of up to 16.5 °C and 28.4 °C, respectively, compared with the traditional roof. This work reinforces that the choice between these two roof types for each city depends on the parameter used for comparison. Based on the relevant information applied to Brazilian buildings and representative climates presented, this work provided recommendations for urban planning policies and building regulations in Brazil. [ABSTRACT FROM AUTHOR]

Green infrastructure has been applied in urban areas to mitigate the negative effects of urbanization and promote the efficient use of resources. This study suggests a methodology for assessing the economic value of installing green roofs and green walls in public buildings, particularly in primary schools. The economic evaluation considers costs and benefits from three perspectives—(i) infrastructure, (ii) users, and (iii) environment—using three levels of analysis (i) financial, (ii) economic, and (iii) socio-environmental. The methodology is applied to ten alternative green roofs/walls scenarios in two primary schools in Lisbon, Portugal, for validation purposes. The cost-benefit analysis is carried out for a 40 and 50-year life cycle, using a 6.67% discount rate. The results show that all scenarios are feasible. The final benefit-cost ratios range between 3.01 and 34.99. A sensitivity analysis shows that the installation cost, esthetic improvement, and increased sound insulation have a significant impact on the results. [ABSTRACT FROM AUTHOR]