Having a high demand for materials and vast emissions, cities are ideal laboratories for exploring the circular economy. The circular city as a city label has attracted a lot of attention from academics and practitioners. However, it remains unclear what a circular city is in the context of the circular economy in the urban environment. To improve our understanding of how circular cities have been defined and developed by scholars, this book chapter reviews academic literature. First, we set a search scope of relevant literature using a bibliometric approach to build a database with 109 peer-reviewed articles. Then, we compile a final list of 28 definitions which are analyzed to find the dimensions of a circular city. These circular city dimensions are: system structure, components, principles, goals, and organizational characteristics. In sum, this chapter provides a comprehensive understanding of the current central themes of circular cities and their shortcomings.

Construction activities in the built environment use a vast amount of resources, making the circular economy an attractive paradigm against the linear take-waste-dispose economy to reduce this resource consumption. Within the built environment, this transition encompasses the use of circular strategies across the product life cycle for materials. This entails efforts from multiple stakeholders across the product value chain. In this study we therefore explore how stakeholders engagement can aid the process to arrive at a common understanding of a public sector circular business model (PSCBM) in the case of a circular concrete paver. We conducted a participatory design workshop aimed to design this PSCBM with all relevant stakeholders across the product life cycle were (re)presented. We conclude that the presence of stakeholder perspectives was observed to be necessary in drafting up a PSCBM for a concrete paver, but caution is needed. Outcome-wise stakeholder engagement was necessary to sharpen the dream, indicating stakeholder value propositions, activities required, value trade-offs and to arrive at a relevant set of indicators. Process-wise, stakeholder engagement in this setting was relevant because stakeholders were enabled to share perspectives and challenge each other perspectives accordingly. This leads to the advantage that the practical feasibility of proposed ideas could immediately be challenged. However, outcomes and assumptions should always be cross-validated and updated according to new insights (e.g., relevant outcomes of tests or regulations, latest insights on reuse and recycling innovations). The outcomes are time- and context-bound and very much reliant on the perspectives shared. The findings of this study contribute to our understanding of how stakeholder engagement in a workshop setting, can potentially be useful to strategize about circular products. We conclude that this for example, could help to improve the functional and esthetical requirements for product procurement.