A framework for assessing material Circularity: Integrating key performance indicators across the building life cycle

Material Circularity (MC) is increasingly recognised as a critical strategy for reducing resource depletion, minimising construction and demolition waste, and promoting sustainable practices in the built environment. Effective assessment of MC requires integration across the Building Life Cycle (BLC), with Key Performance Indicators (KPIs) providing measurable insights into material selection, design strategies, sourcing, construction, use, and end-of-life processes. Despite growing interest, current literature lacks a comprehensive, stage-specific framework linking MC criteria and KPIs, leaving practitioners with limited tools to operationalise circularity across all BLC stages. Thus, this study aimed to develop a framework for assessing MC across the stages of the BLC. Under an interpretivist philosophy, using a qualitative choice, the Delphi technique was applied over three rounds with 21, 18 and 17 experts respectively, followed by code-based content analysis to refine criteria and ensure practical applicability. The study identified six BLC stages: Design, Material Sourcing, Construction, Use, End-of-Life, and Beyond-the-Life, and established 10 Main Criteria with 32 Sub-Criteria linked to 40 KPIs. Key findings include reframing material specification as circular material selection, introducing adaptive reuse and closing cycles as new main criteria, and aligning KPIs such as recoverability, predictive maintenance, and supplier engagement to lifecycle stages. The proposed framework enables stage-wise evaluation of circular practices, supports data-driven decision-making, and enhances accountability in MC implementation. This study contributes to the industry by offering a practical assessment tool, to academia by advancing lifecycle-integrated MC evaluation, and to society by promoting sustainable resource flows, reducing material waste, and supporting environmentally responsible construction. • Framework links MC criteria and KPIs across six Building Life Cycle stages. • Delphi method with experts refines 10 criteria, 32 sub-criteria, and 40 KPIs. • Introduces adaptive reuse and closing cycles as new MC assessment criteria. • Supports stage wise evaluation for measurable and accountable MC practices. • Framework offers scalable applicability beyond Sri Lanka to other contexts.