Improving policy coherence for circular cities

Abstract

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.