This thesis explores the challenges and solutions for integrating circular economy (CE) ambitions into building projects, with a focus on overcoming barriers through effective stakeholder engagement.
The research was motivated by the increasing need for sustainable practices in the construction industry, particularly how to align diverse stakeholder interests with CE goals. The central research question addressed is: How can effective stakeholder engagement strategies overcome barriers to implementing circular economy ambitions in building projects?

The research was conducted using a qualitative research approach, combining case studies, document analysis and interviews with key stakeholders involved with CE ambitions in construction projects (Ma and Hao, 2024); architects, contractors, clients and a material recycling facility. Data was gathered from 9 interviews and analyzed to identify patterns in stakeholder knowledge,
attitudes, and power dynamics related to CE implementation. The stakeholder mapping process included the models of Power-Interest-Attitude (Murray-Webster and Simon, 2006) and Salience (Mitchell et al., 1997) to assess alignment of stakeholders, their engagement levels within the management structure and overall barriers and Critical Success Factors that aided in finding a Stakeholder Engagement Strategy for improvement of CE ambition achievement.

The study revealed that knowledge gaps at project initiation, lack of technical feasibility measurement early on, frequent change in project teams and wavering commitment of these new project teams were considered important barriers that hindered effective implementation of CE ambitions in the Bajeskwartier. Consequently, various Critical Success Factors, such as early alignment of stakeholder knowledge and maintained commitment between stakeholders, are essential for achieving CE goals. Additionally, incorporating other stakeholders such as Investors into
the decision-making process was found to be crucial for overcoming regulatory and financial obstacles, such as the lack of implementing circular business models. Finally, stakeholders with high power and interest, such as clients and contractors, were identified as critical for enforcing CE practices, while architects were considered to have a very high intrinsic motivation for implementing
innovative CE ambitions.

The research concluded that an effective stakeholder engagement strategy involves early alignment of CE ambitions, clear communication of goals and ongoing collaboration between current and future stakeholders, and recurrent checking of ambitions and decision on technical, financial, regulatory and design levels can significantly reduce barriers that hinder effective CE implementation. The findings demonstrate that involving key stakeholders early and fostering a shared understanding of CE objectives and knowledge surrounding this topic leads to better project outcomes and stronger commitment to circular practices. The limitations of this research include the focus on a limited number of stakeholders and the inclusion of only one specific construction project, which greatly limits generalizability. Future research could expand on this by examining similar construction projects, while incorporating new stakeholder groups such as advisors. Finally, various obtained barriers, not found within incorporated literature, were present in alternate literature excluded by this thesis' scope. It is therefore recommended future research highlights their literature research specifically on the topics of leadership, commitment and interests, and the general topics of finance, technical and design barriers and Critical Success Factors.