TU.1.A || Circular Economy Buildings – from Research to Practice

Hartmann, Max; Ebert, Samuel

Alongside all effort to reduce environmental impacts, the topic of resource efficiency, of “closing the loop”, reuse and recycling has gained significant awareness and importance, given the limited nature of global resources. This paper aims to contribute to the discussion on how to depict the topic of circularity in combination with existing methods like Life Cycle Assessment (LCA) to balance both challenges without outplaying them. In order to compare and evaluate environmental impacts and circularity at the same time, this paper presents an approach to describe the circularity of material flows of building components, within the scope of the LCA methodology. The approach describes all relevant parameters, which determine the flow of materials during construction, deconstruction and waste processing. The development illustrated the importance to consider not only the building material used, but also the joints of the component layers, the different material and waste categories and the process of disassembling or deconstruction regarding destruction and separability. All these parameters can only be described within the scope of a building component or even a building and cannot be depicted solely by the material. As a result, the paper illustrates the material output flows for different building components regarding the quality of possible circularity levels depending on these parameters and current recycling technologies. The approach does not end by naming different material flows in general, but aims to give quantifiable and transparent results for the material output flows, which can be implemented in resource documentation (e.g. material passport). The results illustrate the necessity for a more holistic approach as well as appropriate differentiation of circularity indicators. The approach aims to answer the following questions for the user: At what point in time do I receive which material, in what quality or condition and to what extent.