Shifting to a New Sustainable Paradigm: Nature-Based Solutions and Circular Design for the Urban Regeneration

The circular economy is an increasingly popular instance in urban studies to create a more sustainable and efficient system for managing resources. Contemporary cities provide high levels of functionality in many areas: from housing to transport, from educational to health services, from employment opportunities to cultural ones. However, in order to ensure their efficiency, urban areas have been planned and built with levels of sophistication and complexity, both material and technological, which, on the one hand, subjects them to hypertrophic and energy-intensive metabolisms that produce huge amounts of waste in the form of solid waste, water, and air pollution, and, on the other hand, makes them extensive anthropogenic habitats, marked by a high amount of artificial surfaces and a low presence of natural surfaces and elements. Both of these factors contribute to increasing the fragility of urban areas, increasing vulnerability, reducing resilience to the impacts caused by global warming, and accelerating processes related to biodiversity loss. Finally, urban metabolism considers cities as complex systems that consume resources and produce waste. To address these challenges, it is necessary to transform our cities into ecosystems using a holistic approach. One condition for achieving this transition is the implementation of nature-based solutions (NbS) that can provide a range of ecosystem services that benefit the urban biosphere. Similarly, adopting the concept of a circular economy by combining different types of services in order to return resources to the city increases the opportunities for regeneration and redevelopment of urban areas with positive impacts on the well-being and health of citizens. The chapter investigates the intersection of the research fields of nature-based solutions (NbS) and the circularity of resources according to an innovative circular regenerative design approach. Starting with a screening of the scientific literature and through the presentation of the results of concluded and ongoing research and projects at the European level, the contribution makes a critical reading of the issues under investigation and defines the specific challenges of urban circularity that can be addressed with NbS and biophilic design. The contribution describes three possible approaches to using NbS (materials, solutions, or infrastructural systems) for the recovery of the built environment and waste for sustainable urban regeneration, defining potential research trends and future development drivers.