Infrastructure between sustainability and necessity. Environmental design and a trans-scalar approach

The contribution interprets Sustainable Development Goal no. 9 as an opportunity to rethink territorial infrastructuring processes beyond the mono-functional and sectoral model of grey infrastructure. Starting from the theoretical framework of Technological and Environmental Design, the essay proposes a trans-scalar and performance-based reading of infrastructure, understood not only as technical work but also as a device capable of producing services, ecosystem values, and social benefits over the medium- to long-term. The reflection is developed through three experiences in Italy: the new PTCP of the Province of Lodi, in which socio-economic values are related to ecosystem values; the Guidelines for the environmental and social quality of interventions developed by the Agenzia del Demanio, oriented towards assessment throughout the life cycle; and the experimentation with ‘Arundo donax’ in the Saline di Priolo Oriented Nature Reserve, which turns an invasive species into a resource for lightweight and reversible infrastructure. The results highlight the need to move from a logic of technical possibility to a culture of design necessity, capable of orienting multifunctional, verifiable, and transferable infrastructural choices.