Abstract
The built environment has drastically transitioned toward the circular economy (CE) to reduce carbon footprint, waste emission, and resource consumption. The circular ecosystem with close collaboration between diverse actors is critical to the sector's CE transition success. However, a holistic perspective on the circular ecosystem of the built environment remains lacking. This paper provides new insights into the complex and intricate dynamics of actor collaborations in the circular building ecosystems on the niche and regime levels. Moreover, this study shows the orchestrating roles of the municipalities and developers as the ‘keystone’ actors in the circular ecosystem. It also stresses the increasingly significant roles of new actors as the driving forces for the socio-technical paradigm shift toward CE in construction. The actor collaboration in the circular building ecosystem has been shifted to more collaborative and multi-dimensional (i.e., top-down, bottom-up, and horizontal). We also map the actor networks using CE principles and explain the importance of addressing incentives for stronger actor collaborations. Finally, this paper provides policy and managerial implications to reinforce collaboration dynamics and CE practices in the built environment.