The growing environmental awareness of the last decades resulted in identifying the construction sector as one of the major targets for improvement. The building sector is responsible for nearly 40% of the global energy consumption, 30% of raw material use, 25% of solid waste production, 25% of water use, 12% of land use, and 33% of the related global greenhouse gas (GHG) emissions (UNEP 2010). This awareness resulted in energy regulations, the implementation of the European Waste Framework and the development of Construction Product Regulations. But before any conclusions can be drawn about the environmental profile of buildings or their components the environmental impact of the entire life cycle has to be investigated, based on the methodology of a life cycle assessment (LCA).
The LCA methodology is a commonly accepted way to assess the environmental impact of products or services. Despite the fact that LCA takes the entire life cycle into account, still many assumptions and methodological choices have to be made throughout a study, which can lead to different outcomes. Two main approaches can be identified: attributional and consequential LCA. Attributional LCA focus on describing the environmental flows within the chosen temporal window, while consequential LCA explicitly aims to describe how environmentally relevant flows will change in response to possible decisions. A key assumption in consequential LCA is that only specific activities will be affected by a change in demand for a product, the so-called marginal suppliers
In this ongoing research, consequential LCA was applied in the context of Belgian construction projects and encompasses two main trajectories. The first one focusses on the LCA methodology in general, for example by developing and analysing procedures to identify marginal suppliers. The second one builds on these procedures and focusses more on the practical implementation with a particular focus on demountable building solutions in the context of the transition towards a circular economy.
Just recently Matti Buyle recieved the Academy Award of the International Life Cycle Academy (ILCA) for best journal paper of 2017 in the category 'Best contribution to LCA modelling’ for the paper ‘Identifying marginal suppliers of construction materials: consistent modeling and sensitivity analysis on a Belgian case’, a study performed in close collaboration with Aalborg University (DK).