An ecological metaphor can enable transitions towards regenerative circular economies. Yet, this potential remains latent because its conceptual development, which is a prerequisite for its practical operationalization, is in its incipient phase and largely vague. To strengthen its epistemological underpinning, we propose a forward-looking interdisciplinary research agenda which brings together theories, ontological positions, analytical approaches, and strategies of action from ecological economics, panarchy theory, socio-metabolic research, process ecology, environ network theory, the constructal law, nature-based solutions, complexity economics, doughnut economics, regenerative economics, and ergodicity economics. The agenda facilitates the concentration, consolidation, and acceleration of theoretical and methodological innovation for the generation and accumulation of a diverse yet coherent body of knowledge on the interpretation of the process of regeneration and for illuminating the ways in which regenerative circular economies may function.

The comprehensive sustainability assessment of urban waste management systems (UWMSs) is crucial for understanding the impact of current and future city strategies aimed at improving circularity and inclusion in cities. In this study we propose a framework for conceptualizing the inclusive circular city (ICC), and we review specifically scientific literature on methodological tools and trends in integrated sustainability assessments (ISAs) of UWMSs. Of the 145 publications reviewed, only 10 % concurrently evaluated social, environmental, and economic aspects, and just 2 % incorporated circularity and inclusion metrics. Publications focusing simultaneously either on social and environmental dimensions or economic and environmental dimensions accounted for 3 % and 17 % of studies, respectively, while 70 % adopted a single-dimensional approach. A notable proportion of studies focused exclusively on environmental impact assessment, predominantly employing life cycle assessment or indicators such as carbon footprint. Social assessments were notably less prevalent, comprising only 20 % of studies. Stakeholder engagement and inclusion metrics were considered in 20 % and 5 % of the publications, respectively. In terms of R strategies, 65 % of the studies concentrated on recycling and recovery, targeting mainly municipal solid waste. To advance our knowledge on ISAs of UWMSs and improve our understanding of their embeddedness in ICCs, future research should: (a) focus on multidimensional, transdisciplinary assessments with an emphasis on strong sustainability-oriented methodologies by including circularity and inclusion metrics; (b) prioritize inclusion and active stakeholder participation in collaborative knowledge creation; and (c) shift the focus from conventional waste recycling and recovery to ambitious circular strategies that retain resources in closed-loop systems.

Product-service systems (PSS) represent a business model that increases material decoupling and decreases environmental risks while providing customer value. PSS can help realize a more sustainable construction industry, which remains among the largest polluting and waste-generating sectors. Systemic change in the infrastructure sector requires client involvement, which is represented by the government. However, establishing circular PSS is challenging due to the complexities, which need to combine the lifecycle approach, customer-client aspects, new contracting, knowledge transfer, technology, and PSS-specific aspects. It requires ex-ante evaluation of real case studies to increase knowledge and understanding. This article presents a first-of-its-kind framework for infrastructure based on the current literature and analysis of five infrastructure pilots in the Netherlands (bridge deck, digital road lights, guide rails, roads). The final multistakeholder integrated circular PSS framework includes i) lifecycle perspective and circularity, a) materials and b) management, ii) customer-contractor relationship including a) customer-perspective b) co-creation aspects, c) client-customer hierarchy, iii) technology perspective (functions and resources) iv) business aspects such as a) network and b) value creation and retention. The framework allows customer-contractor communication and can serve as decision support. It is applicable to circular PSS where the customer has more involvement in the formulation of PSS.

Considering the importance of waste metals for the transition to circular economies, this study follows a bio-inspired approach to evaluate their material and monetary global trade patterns for sustainability and equity. Between 2000 and 2022, the global trade grew by 5 % in trading countries, by 37 % in trade links, by 71 % in material flows, and by 569 % in economic flows. Driven by indirect effects, the average circulation of material and monetary flows ranged between 21.8–34.9 % depending on the demand or supply perspective but showed a declining trend. Due to homogenization, high network redundancy, and low network efficiency the trade remained robust yet outside the "window of vitality" characterizing natural ecosystems. A few, mostly high-income countries dominated the market, consolidating imports of high-value metal waste mostly from low- and middle-income exporters. Policies should address circularity and trade inequities, accounting for environmental and social ramifications throughout the lifecycle of products and materials.

Reimagining design as a transformative practice for realizing a circular built environment is both urgent and important. Many of today's resource problems can be traced back to the way constructions are being designed. The adoption of circular design practices may alleviate these problems. Most previous research has either mapped the boundaries of contemporary circular design practices or pushed those boundaries with new interventions. The lived experiences of designers are, however, often overlooked. Little remains known about what it is like to be engaged in and how to ‘live through’ circular design. This study therefore seeks to understand the practice from the perspective of designers themselves. Through applying an interpretative phenomenological analysis to unstructured interview data collected from ten frontrunning Dutch designers, it explores both the what and how of circular design. Four emergent themes were found that illuminate the experience itself. Circular design is, accordingly, interpreted as a practice which: proclaims responsibility towards the Earth, materializes future-oriented solutions, deals with a multi-headed monster, and involves orchestrating a design ecosystem. These themes are illustrated with narrative accounts of designers' actual experiences. The rich, in-depth insights offer ample learning opportunities to better understand and facilitate unfolding circularity transitions. Circular design is, as such, theorized as a vital practice that can shape the built environment through materializing responsible futures.

Urban infrastructure development is one principal way people are transforming the natural world and their living conditions. It is important for humanity, but it can also cause major impacts to the environment, such as huge amounts of solid waste and CO2 emissions. Considering this, the circular economy (CE) is a promising alternative to the traditional “make, use, and dispose” linear economy model. However, as a strategy for sustainable development (SD), the CE is still in its infancy in the urban transport infrastructure sector. Therefore, this article aims to guide the implementation of CE during transport infrastructure projects. To achieve this goal, a literature review and case study were adopted as the research methods. After reviewing existing well-established CE frameworks, the iReSOLVE (implement, Regenerate, Share, Optimize, Loop, Virtualize, Exchange) framework is recognized as the most comprehensive one. Upon it, an analytical framework containing specific-related aspects of CE in urban transport infrastructure projects (which belongs to meso-scale) is proposed (coined as the 4Wh-iReSOLVE framework). The 4Wh means Who, When, Where, and What. The proposed framework offers insight into potential CE activities for transport infrastructure projects and assists in assessing the performance and impacts of CE of these projects to cover the gap of the neglected meso-scale. Ten circular viaduct project initiatives in the Netherlands are used as case analyses with the 4Wh-iReSOLVE framework. The results present the highlights of the circular viaduct initiatives in the Netherlands, with CE activities categorized into five groups (design-related strategies, general CE strategies, implementation, management, and related digital technologies and materials, as well as environmental sustainability). As verified by several experts of the projects studied, it can be concluded that the 4Wh-iReSOLVE framework is suitable for transport infrastructure project CE analyses and implementations. It can potentially be a suggested guideline in future policy documents.

Circularity is positioned as an alternative model to achieve sustainable prosperity. Lean construction highlights not only building delivery with less but also contributing to sustainable development. However, lean is criticized for reducing waste only within organizational boundaries while neglecting the impact of waste beyond the boundaries. On the contrary, circularity originates to reduce waste in the system and is currently seeking approaches to implement waste reduction in circular production. To speed up the transition to sustainable resource consumption, the co-act between lean and circular construction seems evident. This research studies resource consumption in product-service systems (PSSs), which are acknowledged to reduce resource consumption. This research first assesses the ability of PSSs to slow and close the loops. After this, the research discusses the complementarities of circularity and lean to co-act toward the same goal. The multiple case studies demonstrate that PSSs have the potential to slow and close the loops. However, PSSs are not inherently circular, but each PSS needs to be designed to be circular system-by-system. Furthermore, the theoretical discussion encourages lean to co-act with circularity. The PSSs provide a system view to lean: to reduce current and future waste and to avoid value losses in multiple life cycles.

Realizing a circular economy (CE) has been widely recognized by practitioners and researchers as the key to the transition toward sustainability. Thus far the academic emphasis has been predominantly on economic and environmental aspects. However, the development and implementation of CE initiatives actually rely on extensive collaboration at the societal level. Hence, an understanding of how a more inclusive society can strengthen the transition is warranted. By systematically and critically reviewing the related academic literature, the results of this paper show that sensitivity to inclusion aspects is crucial to alleviate the transitional burdens on society. Seven main aspects were discerned on inclusion: (1) informal waste pickers, (2) e-waste and health risks, (3) accessibility of services/materials/facilities, (4) consumer behavior, (5) corporate and institutional involvement, (6) technology application, and (7) governance measures. Following these insights, a strong sustainability perspective and agenda on the CE transition are proposed by identifying key actors and structuring their interrelationships as an inclusive system.

The inclusion of the informal recycling sector (IRS) in a circular economy (CE) is challenging and it is gaining increasing attention by the academic community in an exponential yet fragmented way. In this narrative review, we demarcate the direct and indirect contributions of the IRS to various domains of the CE by drawing knowledge from relevant literature. First, we capture the modi operandi of different forms of recycling value chains into a typology. We do so based on distinct foci and policy approaches towards the IRS which have been adopted across different countries. Second, we synthesize various threads of information on reported forms of collaboration, tensions, and challenges in the context of urban waste management, into a conceptual framework to facilitate transitions towards circular and inclusive wise-waste systems. Finally, we discuss important aspects related to circular business models and integration approaches towards the IRS, and we propose avenues for further research.

Rapid global urbanization, urban renewal and changes in people's lifestyles have led to both an increase in waste generation and more complex waste types. In response to these changes, many local governments have invested in municipal solid waste infrastructure (MSWI) to implement circular strategies. However, matching and bridging the costly and logistically complex MSWI with the dynamic social context is a central challenge. In this paper we aim to explore the interdependencies between MSWI and the local social system, and then conceptualize and empirically validate the systemic nature of MSWI. We first review the current MSW treatment methods, corresponding infrastructure, and the challenges facing them. Then, we interrogate system-oriented concepts and use two key insights to set up a conceptual model for mapping the interdependencies in a MSWI system (MSWIS). Finally, a case study of the Dutch city of Almere is used to empirically validate the MSWIS model and identify the social systems that contribute to the development of the MSWIS. The analysis reveals that the development of MSWIS is beyond the municipality's control: efficient resource recovery facilities established by businesses under market rules and waste reuse facilities constructed by social organizations/individuals based on their own needs are key pieces of the puzzle to complete the MSWIS. This highlights the ability of the framework to capture interdependencies that go further than just the formal municipal sphere of influence.

The circular economy (CE) has been established as one of the leading strategies to achieve a more sustainable system leading to national and global goals. One of the models coupled with CE is Product-Service Systems (PSS), with service integrated into products to various degree. PSS implementation in the infrastructure sector has been studied to a limited extent, with evidence of circularity lacking. This study analyzed five PSS infrastructure assets: bridge deck, guide rails, road lights, and municipal and provincial roads. Circularity improved in the design, input materials, and availability of secondary materials. A three-step framework is suggested to enable a circular process: incorporating R-strategies and circularity metrics during design, tracking material circularity, and evaluating implemented metrics and strategies. We suggest mandatory data collection by law to allow traceability, transparency, and the establishment of a secondary resource market.

For many islands, the answer to the question “why a locally, self-sustaining, and regenerative economy is needed?” is clear. The struggle often lies in the “how”. Here, we argue that tools from regenerative economics, which follow an island economy-as-an-organism analogy, offer valuable and complementary insights to socio-metabolic research. Indicators from flow-based and information-based ecological network analysis can quantify properties of an island's socio-economic metabolism (SEM) which are related to cycling, resilience, and degree of mutualism, among others. To illustrate the applicability of these methods, we select Samothraki in Greece as a case study. Results show that over the years the island became very efficient in streamlining imported resources, experiencing physical growth as indicated by a substantial increase in its total material throughput. This growth was attributed to a high degree of order (i.e., network efficiency) endowed by the constraining (ordered) part of the linear structure of the island's SEM. The disordered part of its SEM which is related to resilience, played a much smaller role which became progressively more important over the years, albeit to a limited degree. While the island exhibits an increasing trend in its robustness, its value over the years studied was well below what is typically observed for healthy natural ecosystems, and its current SEM has a very low ability to generate internal flow activity and cycling of resources per unit input. This limited robustness is due to the island's dependency on imports but also due to its linear SEM which had a very small number of feedback loops in its network. A scenario analysis showed that a reticulated network structure would theoretically endow the island with increased resilience, and hence robustness, by allowing for more internal resource flow activity to be circulated as regenerative re-investment. This article highlights that methods from regenerative economics can be used as diagnostic tools to assess and monitor the impact of strategies related to circular economy interventions on network properties, and to illuminate their effect on the regenerative potential of islands.

In recent years, there has been rapidly growing interest in Innovation Districts (ID) in urban policy and practice. IDs are touted as catalysts for innovation and economic development involving a wide range of stakeholders often in under-performing neighbourhoods or precincts. Despite the appeal, critique is forming around their linear understanding of innovation, the narrow focus of economic goals and lack of directionality in addressing grand societal challenges. This paper proposes the concept of Mission-Oriented Innovation Districts (MOID). MOID are thought to help design, shape and drive transformative change from a place-based perspective. Methodologically, this paper conceptually reviews antecedents of and draws on a structured search and scoping review of the two popular but disjointed literatures on ID and Mission-Oriented Innovation (MOI). Drawing on an analysis of 99 journal articles, this paper seeks to provide a better understanding about differences and common grounds of the two strands of literature. Five analytical categories are developed and applied to assess and interpret insights from existing publications: (1) understandings, definitions, and objectives; (2) theoretical-conceptual underpinnings; (3) analytical and methodological approaches; (4) evaluation; and (5) governance. We find that there is ample opportunity for cross-fertilization of insights across these two literatures. Based on this in-depth analysis, the contours of a new concept of MOID are outlined through a formal definition of MOID and insights from the analysis are translated into future research questions to inform a transformative agenda for innovation policy.

This is the English report for the first academic study into the Infrastructure As a Service (IAAS) business model as part of the De Circulaire Weg partnerprogram. This research asks the question: Under what conditions does the applied As a Service model on infrastructure lead or not to a higher level of circularity and lower or equal life cycle costs? To answer this question, we followed and evaluated seven pilots that experimented with IAAS in practice at the municipalities of Amersfoort, Utrecht, and Amsterdam and in the provinces of Overijssel, North-Holland, and North Brabant. We looked at the As-a-Service level, the degree of circularity, and the degree of the costs. In addition, we also outlined the underlying circumstances within which the pilots were carried out, such as the organizational, financial, and technical similarities and differences. Overall, we can conclude that each pilot had a unique set of circumstances and that they each walked their own path with the As-a-Service. This demonstrates the importance of contextual conditions for establishing a successful model. We found these conditions in the patterns we discovered in the data from these pilots.

This data article presents a tripartite dataset that formed the empirical basis for a comprehensive bibliometric analysis of the use of city labels denoting sustainable urbanism in the scientific literature (Schraven, 2021). The tripartite dataset was generated using the abstract and citation database Scopus (Elsevier). Dataset A lists 148 city labels denoting different approaches to urban planning and development. It was used to select 35 city labels that specifically address sustainable urbanism (‘sustainable city’, ‘smart city’, ‘compact city’ etc.). Dataset B references 11,337 journal and review articles spanning the period 1990–2019. All retrieved articles contain at least one of the 35 city labels in the title, abstract, and author keywords. This database was used to calculate the frequency of the selected city labels across time, and to analyze the co-occurrences of city labels. It was further used to calculate the future trajectory of scientific outputs using the Logistic Growth Model (LGM). Dataset C entails 22,820 author keywords extracted from across the 11,337 articles. This was used to analyze the co-occurrences of keywords with city labels. The data article describes the methods of data collection and curation, the analysis performed, and the potential for reusing the data for further research. The comprehensiveness of the bibliometric corpus – spanning three decades and 35 city labels – lends itself to further investigation of how sustainable urban development has evolved as a topic in the scientific literature since the 1990s. Furthermore, the robust methodology developed could be adapted to other scientific repositories and, indeed, other research problems and questions.

Considering its relatively low circularity rate (11.8% in 2019), the EU set several waste management targets as part of its roadmap to a circular economy yet the decision about which transition pathway to follow is not trivial. The maximization of circularity in human made systems is intended to function as a catalyst for this transition albeit at the risk of establishing fragile techno-economic systems. To provide insights for a balanced transition to a circular economy its link with the ecological concepts of “resilience” and “robustness” is illuminated by assessing the theoretical robustness of the material and energy flow networks of the EU27 countries between 2010-2018 using Eurostat data. Results show that despite the high degrees of order (efficiencies) which all European countries developed over the years studied, none of them achieved near-maximum robustness. The identified relationships between the average circularity rate and the average energy efficiency with the theoretical robustness of these material and energy flow networks (for the years studied), respectively, suggest that ascendency analysis is a credible tool for supporting policy making. Both on a national and on a local level for developing circular and robust urban waste management systems given data availability. The contribution to the underlying theory of ascendency analysis is the introduction of the concepts of “technological boundaries” and “windows of efficiency” of these human-made networks which are juxtaposed with the “window of vitality” that is often used to describe healthy natural ecosystems. Finally, the limitations of ascendency analysis and directions for future research are presented.

Community-based energy systems are gaining traction among policymakers and practitioners as promising models for implementing a low-carbon energy transition. As a result, there has been a proliferation of concepts in the scientific literature, such as community energy, energy communities, community solar, and community wind. However, what scholars mean by “community” in these contexts is often unclear and inconsistent. This paper provides further conceptual clarity in the field by analyzing how the term of community is conceptualized in the scholarly literature on energy systems, through a systematic review of 405 articles. We combine an author keyword network analysis of this corpus with an in-depth analysis of 183 definitions extracted from these articles and systematically coded across three dimensions: meanings, activities and objectives of communities. Our findings show that the meanings attached to the notion of community and the alleged objectives pursued by communities vary substantially across concepts and over time. In particular, there has been a shift away from a notion of community understood as a process that emphasizes participatory aspects toward a notion of community primarily referring to a place. Furthermore, there is a growing focus on communities' economic objectives rather than their social or political goals. These findings suggest a weakening of scholars’ attention to “transformative” notions of community emphasizing collective and grassroots processes of participation in energy transitions, to the benefit of “instrumental” notions. This trend runs the risk of placing the sole emphasis on the market value of communities, thereby diluting their distinctiveness from more commercial actors.

Probabilistisch ramen van investeringsprojecten neemt onzekerheden over volumes van materialen en prijzen mee in de berekening. Dit geeft besluitvormers inzicht in de spreiding rond verwachte projectkosten en -baten. In dit artikel bespreken we de ontwikkelingen van probabilistisch ramen en de opschaling van projectkosten naar levensduurkosten. Dit opschalen houdt geen rekening met prijs(de)escalatie. Een andere kansverdeling voor prijsontwikkelingen, afgeleid van prijsindices, past beter bij hoe we omgaan met prijsfluctuaties en leidt tot andere uitkomsten.

Many local governments engaging in sustainable urban development also have a growing interest in becoming inclusive too, brand themselves as such and develop policies to become inclusive cities. However, knowing what exactly this entails and how it can be achieved is not always quite straightforward and requires thorough theoretical and empirical exploration. Consequently, we present a systematic deconstruction of the inclusive city concept in order to develop a better understanding of the main features and dimensions; this is done by means of both a bibliometric analysis and qualitative literature review. The results indicate that inclusiveness is multidimensional and comprised of spatial, social, environmental, economic, and political dimensions in which the characteristics of participation, equity, accessibility and sustainability are sometimes interwoven. Overall, the inclusive city is not merely a precondition for the creation of just space, well-being, and environmental responsibility, but also an opportunity to take stock of interests of stakeholders in cities and to create local public value. The findings have implications for urban policy and practice, more specifically, the clarification of the inclusive city concept and conceptual dimensions will provide significant reference for policymakers and practitioners to make prudent decisions in the process of creating an inclusive city.