This paper presents the findings of an interdisciplinary academic exchange exploring the transition towards a circular built environment (CBE), developed over two years of collaborative work at Delft University of Technology’s Circular Built Environment Hub. A key outcome of this work is developing a comprehensive definition of the CBE and the related Scales to Aspects model, which connects the multi-scalar and cross-disciplinary nature of circularity, ranging from materials and components to buildings, neighbourhoods, cities, and regions. It highlights critical tensions, such as the lack of integration between circular strategies and other global challenges. ... Read more

This dissertation aims to contribute to the urgent need for a circular city policy evaluation framework in European cities. By bridging the concepts of circular cities, policy coherence and policy evaluation, this dissertation provides an ex-ante policy evaluation tool, namely the circular city policy coherence framework.
The concept of a circular city is inspired by biological metabolic systems and aims to implement circular economy principles in various aspects of urban functioning, i.e. to minimise the consumption of primary resources and energy, thereby reducing environmental impacts such as waste and emissions. This approach involves redefining urban processes to close, narrow and slow down material and energy flows.
The built environment is included as an area of intervention in most European circular city policies following it is a major resource consumer and polluter through construction and demolition. These policies generally promote a circular built environment by replacing primary raw materials with at least secondary ones, standardising circular practices in design, construction and deconstruction, creating markets for secondary resources and sharing knowledge to integrate circular practices into construction value chains.
However, there are two issues that make the evaluation of circular city policies, and those specific to the built environment, difficult. On the one hand, there is the issue of process: most circular city policies have been in place for less than a decade, and the scale of the built environment makes any policy aimed at changing it a long-term one, making ex-post evaluation impractical today. On the other hand, there is the issue of content: the lack of clear and commonly used conceptualisations of circular cities hampers policy (evaluation) frameworks. Therefore, the aim of this dissertation is to explore the extent to which circular built environment policies contribute to the policy ambitions formulated by cities. This leads to the main research question:
To what extent do circular built environment policies contribute to policy ambitions as formulated by cities?
To answer this research question this dissertation is structured as five independent, but related academic studies.
The first study explores the recent conceptualisation of circular cities as found in the academic literature. It introduces the concept of circular economy and the application of circularity at different levels of the built environment. It then provides a historical narrative from the study of urban metabolism as the dominant analytical lens to the more recently developed understanding of a circular city. Existing perspectives and conceptualisations of the circular city as well as current bibliometric trends are presented.
The second study presents the relationship between a circular built environment and the policy instruments for its implementation as discussed in the academic literature. This is done through a systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. It analyses over 140 articles in terms of circular urban development policies (i.e. circularity, ecological regeneration and adaptation) and policy instruments (i.e. regulatory, economic and information).
The third study proposes the ex-ante circular city policy coherence framework. The framework, resulting from the combination of two existing frameworks for policy coherence analysis and circular city development, is tested using the case study of the Delft University of Technology campus development as an urban development proxy.
Based on document analysis of spatial development and circular economy policies, the fourth study uses the ex-ante circular city policy coherence framework to evaluate the policy coherence - or (mis)alignment and potential synergies - of circular built environment policies in Greater London. The Greater London Authority (GLA) presents an interesting case for examining policy coherence of circular built environment policies due to its authority, governance structure, scale and the notable gap in governance research that has not been fully explored.
The fifth and last study examines an ex-ante policy evaluation of timber construction in Amsterdam, the Netherlands, given its decade-long circular city policy and recent ambitions for mass timber construction. This is done in two steps. Firstly, policy instruments from different policy documents in Amsterdam were identified and analysed in terms of how they aim to contribute to a more circular built environment. Secondly, an agent-based model was built as a tool for policy makers to simulate the emergent interactions and outcomes of selected policy instruments in increasing timber construction in Amsterdam.
Conclusions and implications
This dissertation concludes that the current understanding of a circular built environment does not see the city for the buildings. By advancing a perspective on circularity in the built environment based on the concept of circular cities, this dissertation proposes that while circular built environment policies have improved their overall coherence, particularly through business-led optimisations in construction practices, they fall short of fully realising a circular city as envisioned by the circular city policy coherence framework. The circular built environment policies of London and Amsterdam are increasingly designed to mitigate issues such as resource depletion and waste generation. However, their policies largely overlook a broader, more systemic approach, particularly in terms of assessing the need for new buildings, maintaining and adapting the existing building stock, and involving residents and communities in the development of a circular city.
The main contribution of this dissertation is to problematise circular built environment policies in relation to circular cities, with a pioneering evaluation of such policies in London and Amsterdam. It positions the built environment as a key component of circular cities, highlighting the influence of policy decisions on the design of the built environment. The work includes the first systematic literature review of policy instruments for circular built environments, identifying a technocratic trend and a focus on looping measures. It also presents an ex-ante policy evaluation framework for circular cities, tested in Amsterdam and London, which allows the assessment of policy coherence and potential impacts, complemented by an agent-based model to visualise interactions and emergent properties between policy instruments.
The circular city policy coherence framework is currently the only one (to the best of the author's knowledge at the time of writing) that not only integrates both process and content aspects within circular city policies, but also allows for the analysis of policy alignment and synergies between different urban policy areas.
Policy makers could use this framework to design more ambitious and well-rounded policies that include all three circularity actions. The policy coherence factors would provide the necessary justification to refine existing policy objectives and instruments or to propose new ones for future implementation, as well as to detect where or how a more systemic perspective of a circular city can improve its policy development.
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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. ... Read more

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. ... Read more

As European governments adopt new circular built environment policies to cope with the socio-ecological crisis, the need for evaluating such policies gains in urgency. Ex post evaluation is, however, difficult as these policies have not been in place long enough to have had significant effects. Nonetheless, ex ante policy evaluation may be possible by assessing policy coherence or the alignment and synergies of policy goals, instruments and implementation practices. This paper proposes a framework to analyse circular built environment policies. This framework is based on a combination of two existing analytical frameworks: circular city development and policy coherence analysis. The framework is tested for the case of a circular built environment in campus development at Delft University of Technology in the Netherlands, which is regarded as an urban development proxy. Policy documents and semi-structured interviews were analysed and coded. Results confirm previous findings about a prevailing focus on looping actions and indicates limited policy instrumentalisation across governance levels. Identified multilevel (in)coherence in circular city policy is pointed out as consequence of siloed-led and supply chain-based thinking and underdeveloped circular policy frameworks. Finally, the analytical benefits of circular city development and policy coherence frameworks are discussed. POLICY RELEVANCE Circular economy policies are conceptually limited in delivering a more circular city and built environment. By proposing and testing a circular city policy coherence framework, this article reveals the limited effect of circular economy policies in coping with unsustainable urbanisation. Policymaking and implementation for circularity in the built environment require frameworks that embrace urban complexities instead of reductionist approaches seeing the built environment as a mere agglomeration of supply-chains. Policymakers may use the proposed circular city policy coherence framework as a tool for ex ante policy evaluation in diverse areas of urban development, and specifically for built environment interventions. The combination of both content-and process-based frameworks enables the identification of possible (in)coherence in current and future policy goals, instruments and implementation practices. This can improve policy in early stages of implementation and create more effective policy outputs and outcomes in the long term. ... Read more

Dozens of cities around the world have already envisioned a circular built environment by establishing a variety of sectorial policies, strategies, and roadmaps, among other policy documents. As circularity is introduced in the making and operation of the built environment, caveats have been raised upon the governance of circular transitions. Policy coherence – or the extent to which policies are well-aligned and create synergies for implementation – in circular built environment research remains an unaddressed aspect of policymaking that, when lacking, may affect the transition’s effectiveness. This article aims to synthesize what policy coherence entails and how can it be assessed particularly in the transition towards a circular built environment. To do so, we developed a two-step approach. Firstly, resorting to academic literature we developed a framework for policy coherence and combined it with an existing framework for circular city development. The resulting framework combines four elements: policy levels, dimensions of coherence, actions for circular city developments, and levers for circular development. Secondly, we tested our framework for the transition of Delft University of Technology’s campus, in the Netherlands, towards a circular and carbon-neutral campus by 2030. Results show that the campus transition policy is increasingly improving its coherence, however, a narrow focus on looping actions over ecologically regenerating and adaptation ones may hinder a more integral campus development in the coming years. A circular city development perspective offers the opportunity to embrace more holistic goals, instruments, and implementation measures. Valuing policy coherence as desirable, our framework highlights the benefits and difficulties towards improving coherence. It also shows the importance of understanding the circularity imperative embedded in policy documents by policy makers formulating and implementing the policies for more coherent transitions in the built environment. ... Read more

The built environment plays a central role in the transition towards the circular economy as they concentrate major consumer and polluter human activities. However, the way BEs are – and need to be – driven by policy to reach cities’ circular goals is still an under-researched aspect. Particularly, there is limited knowledge of policy instruments aimed to foster the transition towards a circular built environment. Therefore, we conduct a systematic literature search and a review of scientific publications to characterize the relation between the circular built environment and policy instruments suggesting its implementation from a circular city development perspective. We do so by answering: (1) how many publications elaborate on CBE policy instruments, (2) what type of circular actions in relation to circular city development are mentioned, and (3) what policy instruments are proposed to implement a CBE. The literature search is performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our results show that 53% of publications address policies instruments for circular built environment transitions. Although different circular actions are identified, looping actions prevail. Adapting and ecologically-regenerating actions, which are essential for circular city development, remain insufficiently researched. Finally, among policy instruments for circular built environment implementation there is a clear tendency towards regulation as means for leverage, which calls for bigger research efforts concerning the mix of policy instruments, as well as in more general challenges in governance and policy coherence. ... Read more

Chilean geography exposes the country to high-level risks such as earthquakes and tsunamis. The disasters of 1930, 1960, 2010, and 2014 testify to the continuous link between human survival and disasters. However, new hazards have appeared ever since –i.e. flood waterlogging, wildfires, and landslides–, highlighting the relationship between current land uses and space occupation with increasing levels of disaster risk. This research aims to determine relations and responsibilities of the Chilean developmental approach in urban planning and territorial governance processes that have created new territories prone to disaster risk. We resort to a longitudinal analysis from 1930 to 2018 at the Gran Concepción metropolitan area as a proxy of Chilean industrialization and economic development approaches. To do so, we developed mixed-approach descriptive research, for which we collected data from national development policies and documented land occupation processes during pre-dictatorship, dictatorship and post-dictatorship periods. Semi-structured interviews with decision-makers involved in current territorial policy were also carried out. The findings show how territorial governance resulted from political visions around different development paths, wherein the concept of risk is weakly perceived among decision-makers. This perception is linked to narrow economic goals and the understanding of land as a barely regulated marketable asset, profoundly affected by segregated urban planning. ... Read more

The built environment (BE) is of fundamental importance in the transition towards circular economy (CE), for it concentrates major consuming and polluting human activities. CE in the BE research has rapidly increased in recent years. However, aspects concerning its policy-making and -implementation, governance, and management are acknowledged to be widely over-looked. Such context may jeopardize effective implementation of circular built environments (CBE). In this article, I conduct a systematic literature review to characterize the relation between circular built environments and the policy instruments suggested for its implementation. Results show that only 7% of publications address policy and instruments for CBE implementation. Yet, identified publications seem to cover a wide variety of policy instruments according to prevailing classifications. Finally, operationalized concepts in publications mostly relate to technological aspects of CBE implementation, which calls for increasing research efforts over systemic challenges in governance, and policy integration and coherence. ... Read more

This paper assesses the potential of the circular economy (CE) policy ambitions of the port cities of Ghent (Belgium) and Amsterdam (The Netherlands). Both Ghent and Amsterdam are municipalities that potentially lend themselves ideally to set up a more local-oriented circular (re)production and (re)consumption system. Subsequently, both have the ambition that, in 2050, the CE will have become an achieved public value that influences all activities to be more circular in comparison with today. However, while having ambitious policies is important, we explain that a public value also requires alignment with the operational capacity used or needed to achieve this policy ambition. In this paper, we focus on the ‘negative’ CE operational capacity: landfills and incinerators. Our results show that the CE ambitions of Ghent are more realistic than Amsterdam. During the last few decades, Dutch waste management has been largely privatized. This led to a significant increase in incinerator capacity and a lowering of the incineration price. This differs from Flanders, which has a deliberate capping on the allowed incinerator capacity, keeping the price for incineration high. This increases the incentive for urban and maritime actors to climb the waste hierarchy, eventually thus making the port city (potentially) more circular as a whole. ... Read more