Modelling life cycle impacts of recycling and reuse of building components

In life cycle assessments (LCA), the environmental impacts of the different stages of a building’s or building product’s life cycle are evaluated in the Modules A, B and C. Module A includes the product stage, as well as the construction stage, Module B describes the use stage and Module C the end-of-life stage according to EN 15978 and EN 15084. Module D summarizes the positive and negative impacts beyond the system boundaries of the studied life cycle.

Our study focuses on Module D1, which shows the potential of reuse and recycling of construction components and materials in their next life cycle. Although the general approach to modelling such impacts has been introduced in the new EN 15804+A2:2019, its application to scenarios with multiple recovery options (such as recycling and reuse), and to materials with specific LCA features (such as open/closed loop recycling or carbon sequestration) needs to be further clarified. The study is based on the methodology developed in the ADVANCE project for assessing Module D1 of constructional steel [1]. A building component made from three material options, which are timber, reinforced concrete and steel, is evaluated for different reuse and recycling scenarios to show the method’s applicability. The selected building component is part of a preliminary design of the Finnish “Circular Drifter” building by VTT and Aalto University [2], developed to promote Design for Disassembly (DfD) and simplified reassembly. In this study it is shown that the methodology given in EN 15804 and further developed in the ADVANCE project can be applied to commonly used structural materials and it shows the environmental potential of their reuse and recycling accordingly.