Despite growing government and market interest to use Circular Building Hubs for reusing construction components, few academic articles have been written about them. We know little about the potential of hubs to answer to the challenges of reuse in the present and future, and their potential to drive systemic changes towards a circular economy. Using various qualitative research methods, this article aims to respond to this research gap by applying social practice theory and the multilevel perspective on past and future practice reconfigurations within the system-of-practices in which these hubs reside. Results show that within hubs reconfiguration from demolition to deconstruction and repair and refurbishment practices have been developed. However, selling components remains challenging, and procurement for reuse and design skill remain underdeveloped. Practitioners expect the system-of-practices to professionalize in the coming years, resulting in market growth for secondary components. Long term, practitioners expect hubs to shrink or disappear because the balance between supply and demand will be controlled digitally. Hubs are therefore a driver for the transition, but only as intermediate step, not as solution for a circular economy. This article is particularly interesting for academics studying CE and transitions, and policy makers interested in developing Circular Building Hubs.

We see unprecedented weather causing widespread impacts across the world. In this perspective, we provide an overview of methods that help anticipate unprecedented weather hazards that can contribute to stop being surprised. We then discuss disaster management and climate adaptation practices, their gaps, and how the methods to anticipate unprecedented weather may help build resilience. We stimulate thinking about transformative adaptation as a foundation for long-term resilience to unprecedented weather, supported by incremental adaptation through upgrading existing infrastructure, and reactive adaptation through short-term early action and disaster response. Because in the end, we should take responsibility to build resilience rather than being surprised by unprecedented weather.

The architecture, engineering, and construction (AEC) sector is in need of a transition towards a circular economy. This article offers an analysis of two cases with a wide variation regarding project dynamics in the Netherlands. Alignments and misalignments were analyzed between practices concerning seven design strategies for circular design based on social practice theory and concepts from the multi-level perspective. Results show that many misalignments still hinder the transition, mostly concerning the use of secondary resources, such as notions regarding quality, beauty, and safety among project team members or rapid decision-making processes of the municipality that misalign with the uptake of design with secondary resources. This article offers directions for reconfiguration, such as better tuning between project planning and urban planning and taking up a more flexible stance regarding the function of the building. This research is interesting for practitioners and researchers focusing on the transition towards a circular economy in the AEC sector.

Energy-efficient renovation (EER) is a complex process essential for reducing emissions in the built environment. This research identifies homeowners as the main decision-makers, whereas intermediaries and social interactions between peers are highly influential in home renovations. It investigates information and communication barriers encountered during the initial phases of EERs. The study reviews AI tools developed within the EERs domain to assess their capabilities in overcoming these barriers and identifies areas needing improvement. This research examines stakeholders, barriers, and the AI tools in the literature for EERs. The discussion compares the functionalities of these tools against stakeholder needs and the challenges they face. Findings show that tools often overlook methodologies in human–computer interaction and the potential of textual and visual AI methods. Digital tool development also lacks insights from social science and user feedback, potentially limiting the practical impact of these innovations. This article contributes to the EERs literature by proposing an AI-supported framework and outlining potential research areas for future exploration, particularly improving tool effectiveness and stakeholder engagement to scale up the EER practice.

This article aimed to assess the potential impact of policy actions to support mass timber construction through an ex ante policy analysis in Amsterdam. Through a combination of policy coherence analysis and agent-based simulation, the study evaluates 130 policy actions, including 80 specific instruments, for the transition from traditional masonry to mass timber construction. The coherence analysis reveals a predominance of regulatory instruments (62%) and a lack of active economic measures (16%), which limits their impact on circular city development. The simulation tested three instruments - demolition notification, a mass timber subsidy proxy and a carbon tax proxy - to assess their individual and combined effectiveness. Isolated measures, such as material price adjustments, were found to be insufficient due to systemic inertia. However, the combination of subsidies and carbon taxes proves more effective, significantly increasing the uptake of mass timber construction as its cost is reduced and construction companies develop expertise. A key finding highlights the complementary role of recycled concrete in supporting mass timber construction, highlighting the need for integrated policies targeting both mass timber and secondary materials. Improving industry knowledge and expertise is identified as a transformative approach to reducing costs and overcoming barriers to adoption. This research is the first contribution to demonstrate the value of ex ante policy evaluation and agent-based simulation in formulating coherent and effective policies for circular city transitions. Policy makers in Amsterdam and other Dutch cities are advised to implement synergistic instruments, support local material reuse and invest in capacity building to achieve carbon neutrality and resource circularity in urban construction. The findings provide actionable guidance for Amsterdam and similar cities seeking to promote sustainable and circular urban environments.

Although gentrification and its associated changes in residential mobility have been widely studied, surprisingly little attention has been paid to the changing origin locations of gentrification-related residential moves. In this study, we use fine-grained register data from the Dutch Central Bureau of Statistics to uncover changing residential mobility patterns to and within the city of Rotterdam, the Netherlands. We identify that the state-led gentrification process goes hand in hand with the changing socioeconomic characteristics of in-movers and the changing origin locations of residential moves. The city of Rotterdam increasingly attracts middle- to high-income households from other core cities in the Netherlands, a process that we understand as inter-urban gentrification spillover. In parallel, intra-urban moves by economically vulnerable residents are declining, especially toward and within gentrifying neighborhoods. This represents evidence of exclusionary displacement. We conclude that the spillover effects of contemporary gentrification should be understood beyond an intra-urban metropolitan perspective since gentrification in one city can enhance gentrification in another.

Circular economy (CE) is territorialised. Economic activities are spatially embedded; they operate across a variety of scales and are heavily influenced by their spatial context. Yet the CE academic literature and policy frameworks rarely address this dimension. If CE policies are to achieve sustainable development goals and be implementable at a subnational level, these shortcomings need to be addressed. In this chapter, we take stock of the current debates and policy on CE in cities and urban regions, critiquing them from a spatial, socio-ecological and governance perspective. On that basis, we outline a new policy and research agenda to bridge the above-mentioned gap and inform the development and implementation of place-based CE policies.

While tackling sustainability challenges, engineering students confront various uncertainties, including the unpredictability of real-world scenarios, unfamiliar aspects of problems, and conflicting viewpoints among stakeholders. Despite previous research indicating the likelihood of encountering such uncertainties in sustainability projects, it is unclear if students are aware of uncertainty and what specific regulatory behaviors they develop to address them. This study seeks to deepen our understanding of the awareness and regulation of uncertainty by students while they work on real-life sustainability challenges. To achieve this, we observed nine MSc students enrolled in a transdisciplinary course on urban sustainability at a Dutch university of technology. Through interviews, we explored the uncertainties they faced and how they navigated them. Our analysis, conducted through open, consensus-based coding by two researchers, revealed that students primarily encountered the uncertainty of multiplicity, characterized by divergent stakeholder perspectives. Additionally, students increasingly recognized the inherent unpredictability of the challenges over the course. To address uncertainty, students developed three kinds of behaviors to deal with uncertainty: seeking social support from commissioners, coaches, and peers; employing small coping mechanisms to overcome obstacles; and developing attitudes such as empathy, flexibility, and relativism. This study offers detailed insights into how students navigate uncertainty. Moving forward, efforts in uncertainty education should prioritize how educators can positively influence the development of metacognition in uncertainty.

Researchers employ many different approaches to study transitions towards more sustainable futures, of which Sustainability Transitions Research and Social Practice Theory are often used. These approaches offer complementary concepts that are helpful to analyse, explain, forecast, and drive sustainability transitions, e.g. heuristics on changing institutions (Sustainability Transitions Research) or dynamics to change behaviour through practice development (Social Practice Theory). However, despite first attempts, it remains unclear how the approaches can be used together. Therefore, the aim of this paper is to expose crossover frameworks in which these approaches are used together, elaborating on conditions that make this possible, and the strengths and weaknesses of specific crossover frameworks. A systematic literature review has been conducted, investigating the potentials and the limitations for crossovers between Social Practice Theory and Sustainability Transitions Research by analysing the approaches according to the different ontologies and theories and then analysing frameworks that have been created so far. This research elaborates on six crossover frameworks that have been created that all have diverse strengths, such as the ability to conceptualize early transitional changes or finding points of resistance in transitions. All the found crossover frameworks made use of either the multilevel perspective or transition management. Other frameworks of transition research have not been found. This research shows that there has been surprisingly little research to crossover frameworks that incorporate an element of time. The exposition following from this study is interesting for researchers and policymakers working on sustainability transitions and sets an agenda for further framework development.

This closing chapter brings together the main messages from each chapter. It formulates a policy agenda for circular cities and regions. It does so by providing a set of recommendations for policy practice. These are addressed at authorities and policy stakeholders at the international, national and subnational levels.

The urgency of addressing housing challenges in low-income areas is increasing due to widening socio-economic inequalities and the worsening impact of natural disasters. Saint Martin, a small Caribbean island, is struggling to provide affordable housing amidst hurricanes, floods, and heat waves. As a result, there has been a rise in self-organized housing units, which are built incrementally and are susceptible to risks. The main challenge is to balance durability, functionality, and esthetic appeal over time. Inspired by St. Martin’s self-organized units, this article explores housing considerations in low-income, hazard-prone contexts by emphasizing their temporalities. Integrating insights from a formative study, including a literature review and ethnographic research, the paper draws on Stewart Brand’s “Layers of Change” and the concept of “Flow”. The study identifies layers within self-organized units corresponding to durability, functionality, and esthetic appeal. It delves into their connection with building activities over time, unveiling the temporalities of housing considerations. This exploration leads to the proposition of “Designing for a Flow” as a novel design approach. Offering practical insights within a concise framework, the study provides nuanced perspectives on mitigating housing challenges in low-income and hazard-prone contexts.

Increasing resilience to flooding is a complex process that requires horizontal and vertical coordination between institutions in policy making and implementation. This paper explores the effect of institutional coordination on managing flood risk in two cities plagued by flooding. Our results show that efforts on building urban flood resilience can be undermined by lack of proper coordination between urban development, water management and land use planning. We find that this complexity is magnified by the emergence of the concept of resilience as an urban development goal that is increasingly pursued by various authorities, but that is inherently contested in practice.

As circular economy policies are adopted to tackle unsustainable built environment patterns related to carbon emissions and inefficient use of resources, scholars warn about the inadequacy of such policies to support sustainable urban development. Siloed circular economy policies in the built environment have focused on applying circular strategies to construction practices. However, cities as complex adaptive systems require systemic interventions including ecologically regenerative and adaptation actions to bring about a more circular built environment and, ultimately, a circular city. This article analyses policy coherence –or the (mis)alignment and possible synergies– of circular built environment in Greater London. Resorting to a circular city policy coherence framework, through document analysis of planning and circular economy policies and semi-structured interviews, both the state of circular built environment policy is assessed and policy recommendations are provided. Circular built environment policies in Greater London have increased in their overall coherence by means of the application of circular economy principles in construction practices, but less so in bringing about a circular city. The findings contained herein may inform policy making in Greater London and other cities of the world to help improve their circular city policy responses to the complex societal challenges imposed by the ongoing socio-ecological crisis.

Klimaatverandering zorgt tal van nieuwe risico’s voor gebouwen en infrastructuur. Het in kaart brengen van deze klimaatrisico’s is in volle gang, maar de betrouwbaarheid van de beoordelingen die hieruit volgen laat te wensen over en dit maakt de handelingsbasis beperkt. Dat concludeerden de experts die deelnamen aan de eerste Focal Point Meeting van het Red&Blue-programma over klimaatadaptatie.

Urban Living Labs (ULLs) have been implemented in many cities, but their organizational and legal structure has not often been analyzed. ULLs aim to provide a space for different parties to research, develop, and test solutions to urban problems whilst engaging with local communities. Their experimental approach to urban innovation and to public-private collaboration makes flexibility, openness, and informality important. However, ULLs are also confronted with existing legal frameworks, responsibilities, and liabilities. Whilst they aim at shared decision-making and horizontality, they must navigate public and private interests, and interact with local government as well. To understand these dynamics, this article examines the legal and organizational structures of ULLs, the factors and trade-offs that influence it, and the role municipal government plays in in these structures. This article analyzes the different forms and trajectories of ULLs in practice, through semi-structured interviews held in four labs in Amsterdam. Through qualitative research, we found that 1) ULLs are partnerships that exist on a spectrum of formalization, from informal to highly formal; 2) the degree of formalization is influenced by financial, legal, and organizational factors that change over time; 3) each degree of formalization is associated to trade-offs, even if these trade-offs are not explicitly formulated by the people involved; 4) tensions arise from the municipality's double role as public authority and as partner. We conclude that ULLs could gain from clearly identifying the legal frameworks that condition their structure, actions, and future.

Comprehensive understanding of the merits of bottom-up urban development is lacking, thus hampering and complicating associated collaborative processes. Therefore, and given the assumed relevancies, we mapped the social, environmental and economic values generated by bottom-up developments in two Dutch urban areas, using theory-based evaluation principles. These evaluations raised insights into the values, beneficiaries and path dependencies between successive values, confirming the assumed effect of placemaking accelerating further spatial developments. It also revealed broader impacts of bottom-up endeavors, such as influences on local policies and innovations in urban development.

With rapid high-speed railway (HSR) developments in China, HSR-based transit-oriented development (TOD) has proliferated across the country. Although local governments claim that HSR station areas are planned according to TOD principles, some scholars argue that these station areas actually contribute to unsustainable development. This study investigates two main questions: (1) what success factors should be included in a TOD plan for HSR station areas? (2) to what extent are these factors considered in the plans of Chinese HSR station areas? To answer these questions, we use content analysis to compare spatial plans for 15 HSR station areas across China, triangulating the findings via in-depth interviews and field investigations. This study reveals that most of the factors in the plans for HSR station areas deviate from TOD principles, especially in small- and medium-sized cities. We find that Chinese local governments mainly use TODs as a tool to promote suburban expansion around HSR stations.

Gentrification is a process whereby neighbourhoods and their socio-economic composition upgrade through residential moves and social mobility. Relatively little attention has been paid to the spatial aspect of gentrification-induced residential moves. This systematic literature review focuses on the origin and destination of moves to and from gentrifying neighbourhoods, by gentrifiers (movers in) and displacees (movers out). It identifies where, when, and how such research has been conducted and highlights gaps in the literature. Our results suggest that the destination of displaced households has been studied extensively, while an understanding of the spatial origins of gentrifiers is lacking. The few studies dedicated to gentrifiers' origins mostly focus on intra-urban environments, overlooking potential mobility dynamics from outside the city-region. We highlight that capturing both origins and destinations of movers at different spatial scales is necessary to demonstrate how residential mobility creates interactions and demographic interdependencies between neighbourhoods and cities.

The delivery of urban basic infrastructure services is often guided by the modern infrastructure ideal, which aims for technical innovation, economic efficiency and uniformity through long-term, centralized management approaches. In rapidly growing urban centres of the global South, however, heterogeneous infrastructure configurations have long involved multiple systems in varying degrees of coexistence. This paper explores how community-based enterprises – organizations that aim not to turn a profit but rather to generate human well-being – contribute to, complement or conflict with wider municipal solid waste management strategies. It does so through two case studies, focused on Luchacos, a local enterprise turning waste into briquettes in an informal settlement of Kampala, Uganda; and the Self Employed Women’s Association (SEWA), a cooperative of waste pickers in Ahmedabad, India. Drawing on empirical data and policy analysis, the research finds that, given the necessary state support, community-based enterprises can contribute to a range of sustainability and development objectives.