Life cycle assessment of an experimental extensive green roof – a case study

This study aimed to determine the environmental impact of extensive green roofs (EGRs) using a LifeCycle Assessment (LCA) based on an analysis of a 4 m² experimental EGR unit. A literature-based LCA was conducted, covering the first three life cycle stages, followed by a detailed LCA of these stages. The analysis was supplemented with carbon footprint calculations for the individual processes involved in constructing the experimental green roof unit (4 m²). The results showed that the production of green roof components, particularly synthetic materials such as polyvinyl chloride (PVC) and polypropylene, significantly contributes to environmental degradation. The carbon footprint of the 740.15 kg experimental green roof was 0.29 kg CO₂ equivalent per kilogram of green roof system (GRS). While this value is relatively low compared to, for example, selected food products, the environmental impact increases significantly when scaled to actual roof sizes, such as 100 m². Compared to similar studies, such as 150.99 kg CO₂ equivalent per m² for tropical green roofs, this study highlights the variability of environmental impacts depending on climate, materials, and design decisions. Although green roofs are intended to mimic natural ecosystems, current designs often rely on materials with high environmental impacts. Further research into sustainable alternatives and the inclusion of more CO₂-sequestering plant species are necessary to reduce their ecological footprint.