The majority of industrial processes and their supply chains follow a linear model, which is wasteful and inefficient. The transition from Linear to Circular Economy (CE) business models is a growing trend globally, with a focus on recovering and reusing waste materials to decouple economic growth from environmental losses. However, there is a lack of knowledge about the incentives needed to accelerate the transition to a circular economy, and how do they differ across European countries. This research investigates into the Circular Economy concept, focusing specifically on PU rigid foam and its implementation within the European Union (EU). The CE framework seeks sustainable development by moving away from the conventional "end-of-life" approach and adopting strategies like reusing, recycling, and reducing materials throughout production and consumption processes. This study offers valuable insights into the key factors and their interconnectedness in the shift toward a circular economy for PU foam in the EU. The investigation concentrates on three distinct economies: Poland, the Netherlands, and Germany, aiming to underscore the disparities in their progress towards CE. To comprehend regional dynamics, 28 interviews were conducted with stakeholders, academia, and policymakers. These interviews aimed to pinpoint the most influential factors in each region and provide a comprehensive understanding of the challenges and opportunities they encounter. For data analysis, a structured cognitive fuzzy mapping technique (FCM) was employed. FCM is a qualitative modeling method utilizing cognitive maps, graphical representations of variables and their causal relationships, to illustrate a system's operations. Cognitive maps prove invaluable in capturing intricate relationships between variables, particularly in situations where statistical data is limited. The FCM technique involves multiple steps to offer a thorough assessment of the system's dynamics.

Construction is responsible for 38% of CO2 emissions and 40% energy consumption globally. The reuse of construction materials has been receiving increasing attention, including European Union regulations, and cities setting goals to reuse construction materials. This is the case for Amsterdam, which established the goal of reusing 50% of construction materials in new construction by 2030. Part of the challenge of reuse of construction materials in urban areas is to optimize the waste-to-resource loops: finding the optimal scale and location for circular construction hubs—facilities that collect, store, and redistribute construction waste as secondary construction materials. In this paper, we use the supply and demand of timber construction materials in Amsterdam to find the optimal scale and location for construction hubs. We used the spatial simulated annealing algorithm as an optimization method for balancing the trade-off between small and large scale hubs, using cost-effectiveness to compare potential locations and identify the optimal solution. We found that the optimal number of hubs for our study area is 29, with an average service radius of 3 km. This study has implications for policymakers, urban planners, and companies seeking to implement circular economy principles.

Within the framework of 'Blueprints for messy cities? Navigating the interplay of order and complexity at the "Reinventing the City" conference, this paper delves into a critical aspect of circular urban development and the assessment of building material reusability. As cities like Amsterdam strive for greater liveability, resilience, and sustainability, a good understanding of circularity becomes imperative. In the dynamic landscape of urban innovation spanning mobility, renewable energy, climate adaptation, and digitization, our research focuses on the intricate domain of building material reusability. We integrate key factors influencing construction product reusability into our assessment framework. The intention of my ongoing PhD program is to establish a framework that incorporates various factors, including practical, financial, organizational, and others. These factors constitute integral elements guiding our decision-making process. The primary contribution of this study lies in the development of a BIM-integrated method designed to quantify the material reusability value. This method, rooted in numerical analysis, focuses specifically on material life expectancy. The lifespan, or in other words, the age of the material, plays a crucial role in determining the material reusability value. As the initial step in my PhD research, gaining insight into the reusability level involves investigating the impact of age. The benefits of this method are manifold. Firstly, it serves as a forecasting tool, enabling stakeholders to anticipate the amount and quality of materials obtainable from buildings at the end of their life cycle. This foresight facilitates strategic planning for material reuse, recycling, and disposal, contributing to more sustainable urban development practices. Secondly, the method provides vital information about the categories of materials resulting from deconstruction and demolition processes, namely, those suitable for reuse, recycling, and disposal. This insight assists stakeholders in making informed decisions regarding proper equipment and resource allocation for each category, thereby optimizing the efficiency of the overall process. As urbanization continues to reshape our global landscape, cities emerge as catalysts for transformative change. This transformative potential is exemplified in pioneering initiatives like Urbiquay. Urbiquay, embodies the essence of urban evolution, showcasing a commitment to sustainable urban development and progressive methodologies. The method presented in this paper is developed to contribute to such transformative endeavours, particularly in the Logiquay project's Work Package 2 (WP2), which is also my ongoing PhD research. The method's ability to forecast the obtainable materials, categorize them based on reuse potential, and guide decision making on equipment and resource allocation aligns with the objectives of Logiquay, WP2. It bridges the gap between innovative research and practical, on the ground application, offering a pathway for cities to integrate sustainability into their ongoing urban transformation.

Cities in the twenty-first century are increasingly confronted with challenges to incorporate sustainable urban design in light of pressing environmental concerns. The presented project focuses on the clash between new development opportunities and the increasing concerns regarding the sustainability of the construction industry. This research adopts the principles of urban mining as one method to address these concerns; the project explores the possibility of Plugin Facades, a new urban configuration, informed by the circular re-use network. Based on the principles and concepts of Circular Design and Circular Economy in the urban environment, we create a complete methodology to develop a pipeline from material exploration to economics of implementation. Beginning with the use of a novel machine learning tool trained to identify different materials, we implement this to quantify the material repository for all building facades using publicly available images of Google Street View. This approach allows the city itself to be considered as a bank of materials. We then look at the spatial potential and material repository to guide the design proposal of ‘Plugin Facades’. The project uses the neighborhood of Sant Marti in Barcelona, Spain, as a case study, to create a design proposal, presented in both urban and architectural scale. The project proposes a new typology of shared space through data-driven implementation of reused materials in cities. Final outcome is based on the cross-referencing of supply and demand - supply being the accessible volume and demand, the abundance of materials sourced from deconstruction. The plugin potential for non-residential buildings can be envisioned as an extension of the outdoors onto the building facades, where varying public sector organizations and individual private developers retain the ownership and accessibility to the plugin in partnership to help achieve the cities sustainability goals. Ultimately, we find that with its potential to disrupt the conventional construction industry and foster sustainable urban development, 'Plugin Facades' exemplifies the blueprint for a brighter, more resilient future for cities worldwide.