A multi-scale framework for assessing circular economy strategies in the building life cycle

In the last decade, international and European literature and regulatory references have proposed several indexes and metrics for assessing circularity performance in the construction industry to support the transition from a “take-make-dispose” to a Circular Economy (CE) model, in line with the EU Green Deal objectives and the UN Sustainable Development Goals. This proliferation of circularity metrics, assessment tools, and performance indexes evidences the growing interests by policymakers and sector operators in implementing circular practices, but at the same time it may create a redundancy of indicators often diffi cult for building stakeholders to interpret and apply. Hence, the paper – introducing some outcomes of an EU-funded research on the measurement of circularity in the built environment – proposes a simplifi ed framework of Circularity Indicators (CIs) to support stakeholders in assessing the circularity performance at diff erent scales (from product to building) and at diff erent stages of the building process (from design to end-of-life). The framework classifi es CIs by specifi c purposes and scopes, facilitating the translation of policies’ goals into tangible actions and measurable outcomes. Firstly, the paper examines the existing international and European references (regulations, directives, standards, certifi cations, etc.) to extract mandatory and relevant voluntary CIs, then it proposes a dynamic and scalable framework based on 289 clustered CIs, designed to support building stakeholders in evaluating ex-ante and ex-post the eff ectiveness of the application of circular strategies. For validation purposes, the framework has been applied to technological solutions (e.g. PV roof system, modular multifunctional façade cladding, smart fan-coil, etc.). Lastly, the paper introduces statistical insights on CIs highlighting trends, recurrent approaches and areas of improvements, and evaluating the framework’s fl exibility and practicality.