How to link LCA and circularity assessments in the built environment? An exploratory study with two Belgian cases
Main Presenter: Steven Claes
Co-Authors: Wai Chung Lam Michiel Ritzen
The transition to a more circular economy is a political priority within the European Union. With its significant environmental impacts and long life spans, the built environment is a key sector to implement circular solutions. However, a single framework with widely-accepted definitions of circularity indicators is not yet established, and available frameworks and tools are not coordinated. [1-3]. Moreover, the multitude of definitions and indicators regarding circularity does not contribute to a coherent systematic approach, leading to incoherent interpretation and results . While Life Cycle Assessment (LCA) is becoming common practice to quantify the total environmental impact of buildings and their building components, this assessment forms no part of circularity assessment frameworks. Current European standards on LCA of construction products and works (i.e. EN 15084+A2:2019 and EN 15978:2011 respectively) are intended to assess linear life cycles and do not account the implications of multiple or circular life cycles. Consequently, there is a need to expand the current LCA framework with a set of objectively quantifiable circularity indicators. In this study, an exploration was performed to investigate an objective method to link LCA with one of the indicators of the Building Circularity Index (BCI). The explored method combines the LCA framework of the above-mentioned EN standards with the BCI circularity assessment indicator on detachability of the connection type in four ways to analyse the effects of different weighting formulas. This methodology has been applied on two Belgian case studies in which design variants of an external wall are compared. The results show that linking LCA results or mass input flows with a circularity indicator has an effect, and therefore could influence the decision-making in case of a comparative assessment. Moreover, it shows that the decision-making is influenced by choosing whether to assess only a circularity indicator, an environmental impact indicator, or the mass input flows, or when a linked approach of these parameters is applied.