Transition to a circular economy (CE) has become an urgent priority in the construction industry, given the sector’s significant contribution to global material consumption, waste generation, and carbon emissions. While circular strategies are gaining attention, their integration into construction practices remains fragmented, with organisations lacking the tools to assess their progress in adopting CE principles. In particular, there is no holistic and context-specific assessment framework tailored to the building construction sector that captures the multi-dimensional nature of circularity. This study addresses this critical gap by presenting the development of a Circular Economy Maturity Model (CEMM) tailored to the building construction sector. The maturity model is developed through a comprehensive literature review and Expert interviews covering CE strategies, definitions, and assessment needs within construction and related fields. Thematic analysis is applied to define the model’s structure and dimensions. The proposed CEMM comprises six key dimensions: Design Strategy, Material Management, Waste and Recovery, Environmental Impact, Organisational Readiness, and Policy Alignment, each defined across five progressive maturity levels, from Initial to Optimised. The model provides a structured, qualitative framework to guide building construction organisations in assessing current capabilities, identifying areas for improvement, and supporting strategic planning for CE integration. By offering a comprehensive and adaptable structure, the CEMM supports more consistent benchmarking, strategic decision-making, and alignment with sustainability objectives. This research contributes as a foundational tool to advance circular transitions in the construction industry