Towards a circular building industry through digitalisation: Exploring how digital technologies can help narrow, slow, close, and regenerate the loops in social housing practice

The concept of Circular Economy (CE) has emerged as a promising alternative to the current linear economy, decoupling economic activity from the depletion of natural resources and promoting a restorative and regenerative system. The transition of the building industry to a circular one can be achieved through four core resource principles: Narrow (minimising the use of primary resources), slow (extending the lifetime of buildings and products), close (regaining post-use and construction waste through reuse or recycling), and regenerate (minimising toxic substances and maximising the use of renewable resources). These principles provide a framework for exploring the role of digitalisation in the transition of social housing organisations (SHOs) toward circular housing practices, with a focus on European SHOs, particularly those in the Netherlands. This thesis follows a structured format comprising six chapters, with four of them encapsulating the author's published articles. Chapter 1 serves as the introduction, providing a contextual foundation for the research. It outlines the overarching theme of the thesis, which revolves around the intersection of CE, digitalisation, and the built environment, with a specific focus on SHOs. The chapter sets the stage by identifying the gaps in existing literature, emphasising the need for a comprehensive conceptualisation of this emerging research field. It further delves into essential methodological aspects, the problem statement, and the broader significance of the research. In Chapter 2, the research delves into an exploration of the current state of CE implementation in Dutch SHOs and provides insights into the pressing barriers, and potential enablers. A Delphi study conducted with 21 social housing professionals reveals that, as of 2020, SHOs were in an experimental phase, incorporating circular construction techniques in pilot projects. Barriers encompass organisational priorities, operating within a linear system, and a lack of awareness. Also, financial challenges related to the costs of circular materials also emerge as significant hurdles. Chapter 3 develops a framework, the Circular Digital Built Environment Framework, in an exploratory qualitative research approach. This conceptual model integrates CE principles with digital technologies to provide an understanding of their potential applications within the built environment. The framework is constructed through expert workshops, literature reviews, and evaluations of current research and practices, resulting in the identification of over ten key digital technologies. These technologies encompass a broad spectrum, including big data analytics, blockchain technology, and material passports. The framework not only informs subsequent empirical studies but also serves as a valuable guide for scholars and industry practitioners navigating the intersection of digitalisation and circularity in the building industry. Chapter 4 presents an analysis of how enabling digital technologies, identified in Chapter 3, are practically employed in real-life practices, specifically within circular new build, renovation, maintenance, and demolition projects of forerunner Dutch SHOs. Employing a multiple-case study approach, the chapter gathers empirical evidence from three large-scale SHOs through semi-structured interviews, desk research, and extensive data analysis. The within-case and cross-case analyses reveal insights into the types of digital technologies being deployed, their impact on circular practices, and the challenges encountered in their adoption. By examining the real-world examples, Chapter 4 contributes to the evolving domain of digitalisation for a circular building industry. Chapter 5 addresses the challenges associated with data (identified in Chapter 4), with a specific focus on material passports as a crucial tool for circularity in existing housing stock. Employing a multiphase mixed-method research design, the chapter utilises the SCOPIS method (Supply Chain-Oriented Process to Identify Stakeholders) for user a d data mapping. This approach results in a data template outlining the requirements of users for material passports. Subsequently, the study tests this template through a case study, identifying critical data gaps and proposing a material passports framework to address these gaps. By leveraging both digital technologies and human expertise, Chapter 5 offers solutions to enhance data management in the pursuit of circularity within the building industry. The findings contribute to ongoing industry and policy initiatives. Chapter 6, the concluding chapter, consolidates the exploration conducted throughout the thesis. It presents the overarching contributions of the research, offering a summary of the scientific and practice contributions and recommendations derived from the entire study.