Circular Built Environment

This gold open access book presents an integrated perspective on the implementation of circular economy principles across the building lifecycle, developed within the framework of the COST Action CircularB - Implementation of Circular Economy in the Built Environment. It combines research on circular design strategies, conceptual-stage decision-making, and BIM-enabled digital implementation frameworks to support the transition from linear to circular construction practices. The book explores how circularity can be embedded from the earliest architectural and engineering design stages through strategies such as design for adaptability, reversibility, disassembly, modularity, material efficiency, reuse, refurbishment, and lifecycle extension. Particular attention is given to the role of early-stage design decisions in shaping the future environmental performance, resource efficiency, and recovery potential of buildings. Drawing on systematic literature reviews, comparative analyses, stakeholder surveys, and international case studies, the contributions identify current barriers, implementation gaps, and opportunities for scaling circular practices in the built environment. The findings demonstrate that, although circularity strategies are increasingly considered during the design and material selection phases, their integration into building operation, digital lifecycle management, governance frameworks, and circular business models remains limited. As a result, most current applications still focus on isolated interventions rather than fully integrated circular systems implemented consistently across the entire building lifecycle.