A conceptual model for integrating circular economy in the built environment: An analysis of literature and local-based case studies

The built environment is a major consumer of raw materials compared to other industries. In the context of finite natural resources and climate change, transitioning to a circular economy (CE) in this sector is imperative to preserve natural resources and to strive in achieving zero waste and pollution reduction. This study aims to explore the concepts and principles of CE as applied within the built environment discipline. Local case studies from five countries were collected and analysed to investigate how CE practically operates in different contexts. CE in the built environment primarily focuses on 3R strategies of "recycle, reuse, and reduce" while other R strategies, such as "repurpose, rethink, refuse, and regenerate", typically receive less attention. A conceptual model illustrating CE principles and strategies implemented throughout a project life cycle was developed to demonstrate how various principles and strategies can be applied in different project phases using analysis from selected case studies. The study concludes with recommendations to implement multiple R strategies to create higher value rather than relying on lower-order R strategies. The study can assist policymakers, external and internal project stakeholders of the built environment to better understand CE and adopt a circular mindset in building and construction projects.