Circularity metrics and indicators for construction: gaps in current assessment methodologies and recommendations towards a standardized approach

Circular economy is an attractive concept for the building sector, which aims to operationalize sustainability by reducing its embodied emissions and resource consumption. Many circularity metrics have been developed to monitor these strategies, but they rely on heterogeneous methodologies that reflect a lack of consensus on the definition of circular economy. To help building stakeholders decide which metrics to use, we conducted a literature review of circularity metric research published between 2010 and 2025. We then developed a circularity assessment workflow and a taxonomy of circularity metrics across life cycle stages and circularity strategies. Results show that the construction and use phases are not well covered by existing circularity metrics, which mostly focus on closing material loops within design and end-of-life stages. We recommend using the established methods of material flow analysis and life cycle assessment as an inspiration to support the development of appropriate circularity metrics by (1) preserving functional properties of materials, products and buildings, (2) conducting multi-indicator assessments, and (3) returning to a traditional workflow that defines circularity goals and scope before developing tailored metrics (instead of vice versa, as often performed in the literature).