For projects to contribute to sustainability transitions, traditional roles of project actors need to be challenged. This paper focus on the changing role of demolishers in circular construction projects. We explore the role changes needed and the tactics adopted to negotiate these changes. Therefore, we collected data across 10 demolishers and two construction projects in the Netherlands. We identified required changes related to task, timing, position, and image. The studied demolishers adopted six different tactics to negotiate these changes. These findings contribute to the sustainability transitions literature by highlighting the important function of projects in operationalizing role changes and enabling change in the roles of incumbent actors. Furthermore, the results contribute to the debate on roles in sustainable projects, and on the roles of demolishers in particular, showing the different elements and non-linear nature of role change, including the unique challenges and tactics adopted by demolishers to negotiate these changes.