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The built environment—with its significant environmental impact and long lifespan—is a key sector in which to implement circular economy principles. So far, however, a coherent framework with circularity indicators has not yet been established. While Life Cycle Assessment (LCA) is commonly practiced to quantify the total environmental impact, it is designed and intended to assess linear life cycles, making it unsuitable for circularity assessment. Thus this paper explores an objective method to link LCA to a semi-quantified circularity indicator. Four variants of external wall designs of two case studies are analyzed. The explored possibilities of linking LCA results or mass input flows to the circularity indicator show differences in outcome. Furthermore, the analysis shows that decision-making can be affected by choice of assessing only a circularity indicator, an environmental impact indicator, or mass input flows, as opposed to a scenario in which a linked approach of these parameters is applied.

Many studies concerning lowering the Operational Energy (OE) of existing dwellings have been conducted. However, those studies barely cover its collateral Embodied Energy (EE). As the Circular Economy is gaining momentum and the balance between OE and EE is shifting, the Life Cycle Energy Performance (LCEP) is becoming increasingly relevant as an indicator. LCEP accounts for all the OE and EE a building consumes during its lifespan. However, clear insights into the LCEP are still to be investigated. This study focuses on developing a circular and energy-efficient renovation solution for a common terraced dwelling typology in the Netherlands. The energy-efficient renovation is based on three circular strategies: Biomimicry, Urban Mining, and Design for Disassembly (DfD), covering the aspects of EE and future reuse of building materials and components. The developed renovation solution reduces 82% of the LCEP compared to the existing scenario. With additional photovoltaic (PV) modules, the dwelling reduces 100% of the LCEP. Applying biomimicry, urban mining, and DfD-based renovation can significantly lower the overall LCEP and its collateral environmental impacts to achieve a Life Cycle Zero Energy circular renovation.