The aim of this paper is to better understand the dynamics of circular construction projects and how these interorganizational projects contribute to the transition towards a circular economy. It is essential that the construction sector develops and adopts interorganizational initiatives to support the transition to a circular and low-carbon construction economy. A benefit of being involved in such initiatives is that organizations reflect on the emergence and acceptance of new practices related to changing organizational roles and responsibilities. In this paper, we study eight circular construction projects within the context of an interorganizational initiative to stimulate the transition towards a circular economy by exploring insights from evaluations thereof. We build upon literature from Sustainability Transitions Research (STR), circular construction research, and interorganizational project studies. Our findings show three clusters of dynamics that are relevant in the realization of circular ambitions in interorganizational construction projects: (1) prerequisites, (2) temporal dynamics in interorganizational projects, and (3) contextual influences. These insights highlight factors that enable the realization of circular ambitions in construction projects and contribute to our understanding of the dynamics of interorganizational construction projects and their role in the context of STR.