Local governments face growing risks from climate change, which require substantial investments in climate adaptation to safeguard future generations. Nature-based solutions (NBS) have been recognized as a cost-efficient strategy to redevelop public space, to create greener and more climate adaptive urban environments. However, development of NBS is hindered by a lack of financial resources to fully scale up the transformation. To overcome this barrier, literature calls for clear sustainable finance frameworks and business model approaches to include private financing in the development of public NBS. In our research we consider the perceptions of municipalities and banks, as institutional lenders, towards using green debt-financing to finance NBS. We draw on sustainability transitions literature to theorize NBS as a niche innovation within established banking-municipal relations. Using qualitative interviews with Belgian banking experts and urban and financial planners from Flemish cities, we reveal competing financial logics between municipal financing practices and banking requirements, limiting the uptake of green debt for NBS. While NBS are mostly absorbed in traditional municipal deficit financing, this conceals their value and prevents market development. Alternatively, project finance remains difficult due to capacity constraints and differing valuation logics. Emerging sustainable finance frameworks create opportunities but shift administrative burdens onto municipalities. Overall, current practices mainly support NBS to fit and conform, rather than transform established debt-practices. Substantial upscaling of NBS will require changes in both banking practices and municipal financing approaches, including explicit integration of physical climate risk and collective financing mechanisms.

Cities worldwide are increasingly seeking to offset the environmental harm of motorway infrastructures in dense urban cores. One prominent approach, tunneling over existing motorways, or “capping”, mitigates harm and creates new green spaces but comes with high price tags that often exceed available public funding. Public value capture (PVC) tools are frequently promoted to bridge these financing gaps. However, while PVC has proven effective for large metropolitan transport projects, its potential for projects in smaller urban settings is far less understood. This study examines that question by estimating the revenue potential of five common local PVC mechanisms for a planned capping project in Antwerp, Belgium. Monte Carlo simulations indicate that, collectively, these tools could cover only about 8% of total investment costs. The modest return underscores the limited scalability of conventional PVC in smaller urban contexts. The paper calls for adaptive, context-specific value capture strategies that better monetize the broad public benefits of capping projects, while cautioning against treating them purely as funding sources.

A nature-based solutions (NBS) approach to integrated urban water management is increasingly being recognized as offering an ecological and cost-effective alternative to gray infrastructure and additional co-benefits. However, despite growing support, the upscaling of NBS remains limited. Using a case-based approach, we examine how existing governance structures and financial mechanisms are supporting this shift toward an NBS approach in the Belgian city of Genk. Our findings highlight the importance of aligning existing financial mechanisms with alternative funding options to support NBS scaling. We propose three strategies for urban NBS planners to navigate the existing financial landscape: bridging the knowledge gap on public financing mechanisms, mapping the outcome of financial mechanisms early in the planning process, and adjusting NBS planning adaptively to fit current mechanisms and fill gaps. This underscores the need to reevaluate existing governance and financing frameworks to effectively scale-up and ensure projects progress beyond the pilot stage.

Extensive research highlights how local developer obligations (DOs) are increasingly used by local governments as value capture tools to generate new funds for spatial investment. This article examines why DOs have become a central focus and how their use affects urban planning and development. Using the case of Antwerp, Flanders, and its Urban Development Cost (UDC) policy introduced in 2016, it argues that the motivations for using DOs extend beyond financial considerations. In Antwerp, the UDC serves as a political instrument of statecraft, allowing the executive branch of the city's democratic structure to create discretionary revenues and consolidate control over them. This centralization of power is obscured by a technocratic approach that standardizes UDC negotiations through calculative practices. Stakeholder interviews further reveal concerns over the mechanism of the UDC, citing diminished democratic oversight, power imbalances, and uneven geographic and economic impacts. The findings highlight the need to further examine how (sub-)local political dynamics shape the financialization of value capture and influence its legitimacy.

Urban underground space (UUS, i.e., built environment) is considered a valuable and non-renewable resource, and considerable research has been devoted to attaining sustainable UUS use. However, UUS use remains mostly characterized by an ad-hoc, first come, first served, or last resort practice which leads to unsustainable development of the urban underground. As more cities realize the importance of the subsurface, there is a growing need for a structured framework for upscaling sustainable UUS practices and transitioning toward a sustainable use of the subsurface. This article investigates how transition management (TM) as a governance theory and operational policy model, aimed at dealing with long-term desired change and sustainable development, can guide the necessary change toward sustainable UUS use. The research connects two streams that have not been closely aligned in the past and focuses on the question: How can transition management help in making sustainable UUS use more common practice? By applying TM key characteristics and instruments to the dysfunctional system of UUS space we demonstrate feasible pathways to upscale sustainable UUS practices.

This study explores the recent shifts in urban policy in Shenzhen, China, through the analytical lens of Peter Hall’s policy paradigm theory. China has experienced rapid urban development since the Chinese economic reform in 1978, resulting in the creation of urban villages (UVs) in the large metropolitan areas with specific civil rights for its inhabitants. Recently a shift is occurring in Chinese urban policy from demolition and reconstruction towards preservation and renewal of these urban villages. By applying Hall's framework, we aim to understand whether these changes in urban policy in Shenzhen signify merely a shift in tactics or represent a broader paradigm shift in response to evolving economic conditions and policy perspectives in China. While our study is centred on Shenzhen, we suggest that similar changes are likely to occur in other Chinese cities in the near future. Through this lens, we offer novel insights into the complex dynamics of urban development and their relationship between changing social and economic conditions. This research is particularly relevant for policymakers, urban planners, and scholars in urban studies.

Climate-related challenges are forcing a systemwide spatial reorganisation of Europe’s metropolitan areas. The region of Flanders is an excellent example of this mission. This article explores opportunities for a new mode of spatial organisation in an extremely sprawled urban region. The challenges for a climate-neutral built environment, energy supply and accessibility can be addressed more effectively by integrating mobility and transport policies in a polycentric interconnected urban system of distinct places. Although this article discusses the Flemish case and its historical particularities, our recommendations also benefit other sprawled regions in Europe.

Climate -related challenges are forcing a systemwide spatial reorganisation of Europe's metropolitan areas. The region of Flanders is an excellent example of this mission. This article explores opportunities for a new mode of spatial organisation in an extremely sprawled urban region. The challenges for a climate -neutral built environment, energy supply and accessibility can be addressed more effectively by integrating mobility and transport policies in a polycentric interconnected urban system of distinct places. Although this article discusses the Flemish case and its historical particularities, our recommendations also benefit other sprawled regions in Europe.

As climate change continues to impact cities, nature-based solutions (NBS) are being advanced as important adaptation strategies for mitigating these negative effects. As is the case throughout Europe, Flemish cities have enacted adaptation policies and plans outlining the importance of NBS. Nevertheless, the implementation of NBS has been slow. Local governments identify financing as an important barrier. Although private financing is often proposed as a solution, few studies have applied a public-financing perspective to generate insight into and remedies for such issues. In this article, we examine how four Flemish cities are financing NBS implemented in public spaces as climate adaptation strategies. Based on a multiple case study approach, our results uncover that different financing strategies are employed during the design, implementation and maintenance phase of developing NBS projects. Additionally, we learn that the interplay between policy and financing becomes an important catalyst for investments in public NBS. We identified three approaches administrations use to secure (public) resources. During the design phase, support is developed within the administration and politically through (1) fostering internal collaboration by developing integrated spatial NBS designs. In the implementation phase resources are attracted by (2) putting the developed spatial designs to work and seizing available funding opportunities. During the maintenance phase (3) strategic partnerships are established with NBS beneficiaries to alleviate costs for municipalities. We conclude that, in the absence of more long-term forms of public financing, these approaches offer smaller cities tools to overcome the financial barrier.

Complexity in megaprojects leads to uncertainty about the future, which means forecasting is difficult, and perceptions of uncertainty can differ among stakeholders based on differing interests and values. We contribute to uncertainty and stakeholder management research and practice in megaprojects by conceptualising perception of uncertainty and by adopting Q methodology as a mixed method for stakeholder analysis to empirically study stakeholders' perceptions of uncertainty in the Flemish A102 road project. Four perception groups are revealed that show why understanding perceptions of uncertainties in megaprojects matters: (i) uncertainty management must be broadened by considering relations between uncertainties; (ii) assessing whether uncertainties are irreducible or reducible and how they should be managed can be perceived differently; (iii) stakeholder analysis must aim to understand stakeholder heterogeneity and avoid classifying stakeholders based on a priori assumptions; (iv) revealing perceptions of uncertainty can help project managers anticipate conflict and prepare for stakeholder dialogue and engagement.

Scenario planning is increasingly used to manage uncertainty, but such planning often struggles to influence decision making and help communities navigate multiple futures. This article proposes a framework for planning practice that integrates scenario planning and real option theory to identify adaptation options that make plans or projects responsive to multiple futures. The framework is explained through a demonstration case, Plan Bay Area 2050 and Link21, based on document content analysis and expert interviews. The findings show that exploratory scenarios generate opportunities for real options reasoning and adaptive planning, by making uncertainties explicit when thinking about the future.

Nature-based solutions (NBS) are widely regarded as cost-effective responses to climate change and environmental degradation that also provide numerous co-benefits. However, despite significant policy attention, NBS plans often fail to materialize due to public budget shortfalls. Alongside traditional public finance, the international debate increasingly urges the mobilization of private capital for NBS through alternative financing (AF) techniques. In this scoping review, we examine the literature on a) the AF models connected to NBS and b) the drivers and barriers associated with these AF models in terms of their financial technicity and their embeddedness in the political, economic, social, technological, legal/institutional, and environmental/spatial (“PESTLE”) context. Although many models are discussed, the results indicate that none can be considered full substitutes for traditional public finance. Barriers and drivers converge around seven overarching tensions: new revenue and risk distribution vs. uncertainty, budgetary and legal pressure vs. political willingness and risk aversion, market demand vs. market failures, private sector engagement vs. social acceptance and risks, legal and institutional conduciveness vs. inertia, and upscaling potential vs. environmental risks and land use. Future research should focus on a) how to further integrate NBS monitoring, quantification, valuation, and monetization into AF models, b) systemic and empirical approaches to improve the understanding of the applicability and transferability of AF models, and c) an exploration of the potential qualities and social risks of AF models in NBS governance arrangements.

Urban designs, and in particular urban masterplans, must deal with an inherently uncertain future. However, in practice, many urban masterplans still seem to underestimate or even ignore uncertainty. Some scholars have proposed design flexibility and adaptivity as a way to deal with uncertainties, but a formal framework has been lacking in urban design theory. Drawing upon theories of real options in finance and economics, a framework for design under conditions of uncertainty is developed. Five generic design strategies are identified, offering different flexibility options to urban design. Although such design options are currently used in practice in an intuitive way, the real options framework allows designers to cope with uncertainties in a more structured way and offers the possibility to quantify the added value of flexibility options.

This paper asks why uncertainties are avoided in dominant megaproject practice while planning scholars are increasingly advocating adaptive planning and uncertainty acknowledgement. We propose a novel analytical framework to explain uncertainty avoidance, consisting of two current explanations - resource constraint and strategic behaviour models - and a complementary institutional model. We apply the framework to a seaport megaproject in Flanders to test its validity. Results show that the institutional model increases our understanding of uncertainty avoidance. More attention to planning institutions and far-reaching institutional changes are required to facilitate a move towards uncertainty acknowledgement and adaptive planning.

Megaprojects are complex and contain multiple risks and uncertainties. The dominant 'predict and control' planning method mainly ignores risks and uncertainties, making megaprojects inflexible and vulnerable to unforeseen changes. Insights and methods from real options theory (ROT) in economics and finance have the potential to improve planning of megaprojects in three ways: (a) better management and assessment of risks and uncertainties, (b) a more transparent and explicit identification and communication of risks and uncertainties, and (c) a monetary valuation of flexibility. An in-depth literature review of 42 papers of real options applications to megaprojects serves as a benchmark to analyse if current real options literature meets these three expectations. Through this review, we identify the main trends, relevance and research gaps. While its theoretical relevance is illustrated, three main gaps impede real options' practical relevance for megaprojects: the applications paint an incomplete picture of megaprojects; its mathematical complexity; and the lack of empirical evidence of real-life cases. Based on a plea for more interactive research between scholars and planning practitioners, we provide an agenda for further research as to how ROT can better meet its expectations and fulfill its potential for the planning of megaprojects.

Virtual reality (VR) is a rapidly emerging tool in design and architecture. VR allows to define and evaluate design equations at full scale providing the user a sense of depth, volume and distances, as opposed to drawings, plans and CAD designs displayed on screen. Currently, VR enables to provide subjects with a preliminary experience of their own body and relative position towards the virtually designed space. That real time virtual body experience is expected to become more realistic the forthcoming decade, given the uprising of motion tracking and posture generating algorithms, and the expected breakthrough of augmented reality. These evolutions will make VR a tool that is complementary to design and simulation of body near products with 3D anthropometry and rapid prototyping such as 3D printing. Whereas the latter allows simulation of interaction with artifacts at scale of the human body or smaller, VR will enable to simulate and evaluate structures that surrounds the human body: rooms, spaces, buildings and urban implants. In particular, evaluation of scale with relation to human proportion is expected to benefit from VR. The present research is a first step in comparing classical drawing techniques with VR. This paper is confined to evaluate the aesthetic preference of subjects when exposed to facades in a virtual urban planning environment. The preference for a certain proportion is evaluated by exposing subjects to the same facades in both mediums. In this first pilot study, we isolated one variable: the length to width ratio of windows in the facade of a house with a flat roof. Subjects were primed with three length to width ratios: the square root of 2, the golden (in approximation 1.618) section and a value that was intuitively designed to be most pleasing, turned out to be 1.80. A total of n = 30 subjects were enrolled in this study. Only descriptive statistics were used due to small sample size. Results were interpreted as tendencies. There were no differences found in preferences when exposed to drawings compared to when exposed to the same models in VR. These results indicate that-restricted to our simple and controlled setting- evaluation in VR coincides with regular evaluation techniques, and thus could extend the latter, not only to relative proportion, but also in relation to subject's body dimensions as a sense of absolute scale. The test setting presented in this pilot can be used to plan large scale-controlled studies to further investigate this hypothesis.

Complexity and uncertainty are inherent to megaprojects. While the social cost−benefit analysis (SCBA) and environmental impact assessment (EIA) are increasingly used to support decision making (DM) in megaprojects, these instruments often ignore and avoid uncertainty communication, documentation and analysis. By using a conceptual uncertainty matrix for decision-support analyses, this paper questions how uncertainties are taken into account in the SCBA and EIA when making decisions. A document analysis is applied to the SCBA, EIA and other project documents from the research (planning) phase of an ongoing sea port megaproject in Zeebrugge, Flanders. The results show that uncertainties are barely documented nor analysed in the SCBA and EIA, but arise later during the DM process; mainly about which plan alternative is the best for achieving the project's objectives. Uncertainty or ambiguity about ‘the best alternative’ results from stakeholders’ different interpretations of the SCBA and EIA. The paper reveals that research about megaproject uncertainty and DM should not be limited to the boundaries of either an SCBA or EIA but to further extend the scope to look at the dynamic interplay between uncertainties like multiple decision-support instruments, stakeholders’ different interpretations of these instruments and perceptions about uncertainties, DM and the general process.

This article discusses the challenges and opportunities identified in the implementation of the Citylab project in Latin America during the period of 2015-2018. The project was funded by the Erasmus+ Key action 2 programme of the European Union. The project aims to innovate teaching for sustainability in higher education institutions through Problem Based Learning (PBL). Opposed to traditional teaching methods, the pedagogical approach of PBL is a learner-centred approach that takes a complex problem as point of departure instead of existing established knowledge. Since application of such learning methods is limited in Latin America, the Citylab project attempts to introduce PBL in the existing curricula of 12 Latin American universities through the implementation and development of interdisciplinary Citylab modules focusing on sustainable urban development. First, the role of PBL in education for sustainability is discussed in a broader theoretical context. Second, the goals, implementation strategies and results of the Citylab project will be presented. Third, we highlight some critical issues and success factors experienced during the project. The findings of this paper are based on (1) self-reported questionnaires from the partners at the end of 2017; (2) on-site visits by the authors and expert visits; (3) focus groups, interviews and conversations with project leaders of the participating institutions during the project. Depending on the institution, the project results were varying in terms of innovation and upscaling potential. Critical factors were related to the role of the project leader in the organization, the flexibility of the implementation and cultural differences. Internal regulations created both incentives and disincentives for participation. Competitive elements in the project and available resources for equipment can act as stimulators in some cases. The challenge lies moreover in detecting windows of opportunities for change in order to accomplish curriculum reform and by doing so, pursue continuation of the PBL approach after the project’s horizon.