Sustainable re-use of spaces and buildings: application of the principles of circular economy to urban regeneration

Cities are complex systems subjected to continuous transformations. The changes in society and the different production requires the redesign of urban spaces, often favouring some areas and marginalizing others. As time goes by, buildings change their usefulness, remaining unused and abandoned. The consumption of new land for new buildings, together with the production of waste materials from the demolition, contribute to burdening the negative balance of the city system in consumption of resources and production of waste. With regard to the life cycle of a building, similarities can be highlighted with the life cycle of a commodity. In the current debate, production process are shifting according to sustainability criteria. By innovative solutions, it is possible to rethink production processes, enhancing for example the use of secondary raw materials and by-products, creating the conditions to minimize negative impacts, implementing recovery and reuse, as well as by the adoption of responsible solutions. Today, public decision-makers must define urban planning policies capable to guarantee, in the long term, a sustainable development in line with the objectives of the United Nations 2030 Agenda. In doing this, policy makers could try to consider the city as a commodity, whose life cycle is made up of continuous use and transformation of flows of materials, energy and ideas. In fact, this approach could offer opportunities for improve the innovation and the sustainability of cities. More, by increasing the level of awareness at the urban level can push citizens towards more sustainable consumption models. Through working groups formed by qualified stakeholders, it is possible to highlight the barriers (i.e. technological, regulatory, and economic) that slow down the full application of circular economy principles. Through participatory processes of co-design, it is possible to assign new functions to unused buildings. This paper aims to describe examples of urban regeneration based on a circular economy approach, taking into account the case of the city of Prato, Italy. In fact, within the city system, the integrated understanding of interconnection between inhabited areas, commercial, industrial areas, green, and agricultural areas, enables the implementation of good circular practices. The paper mainly relates to SDG 11, target 11.3. Thanks to the adapting reuse and the transformation of existing buildings, cities will be more sustainable and resilient in the future, contributing to the increase in the well-being and quality of life of citizens, strengthening their identities, memories, cultures, respect for the environment, contributing to social inclusion and economic growth.