Abstract
Purpose The construction sector accounts for half of the materials extracted in Europe. Furthermore, one-third of the waste generated in Europe is from construction, which holds significant potential for implementing circular economy strategies. This article aims to conduct a Life Cycle Assessment for a novel building block, CleanTechBlock (CTB), to evaluate the environmental impacts of alternative end-of-life (EoL) scenarios based on circular strategies. Methods A cradle-to-grave LCA is implemented for the CTB to assess the potential environmental impacts of alternative EoL scenarios based on CE strategies, comparing them with the conventional disposal treatment of CDW (landfill). Additionally, a sensitivity analysis is performed on the recyclability rate and transportation distance to the EoL treatment facility. A complementary analysis is also performed on alternative insulation materials to evaluate the influence of the EoL allocation method on the potential environmental benefits of foam glass compared to conventional insulation materials, such as expanded polystyrene and stone wool. EoL allocation methods, including cut-off, avoided burden, and the Circular Footprint Formula (CFF). Results and discussion The results show that implementing circular strategies can mitigate environmental impacts at the EoL of CTB. Reusing foam glass yields lower impacts than recycling and transporting waste to recycling and reuse facilities for long distances can still be preferable to landfill disposal. Regarding EoL allocation methods, the cut-off approach does not capture, for instance, the benefits of creating several loops, as different types of materials can be recovered in the same product. Furthermore, an important limitation on the application of the CFF was identified when an open-loop recycling strategy was considered. It can be concluded that EoL allocation methods need to be critically evaluated and adapted to each EoL scenario. Conclusions This article contributes to advancing sustainable waste management practices of building products by assessing the environmental impacts of adopting circular strategies. Further research and methodological improvements are needed in recycling allocation. Particularly on how to address the time aspects of allocating credits for products with long lifespans, and how to account for recycled content originating from different product systems.