Material knowledge and practices in the making of a building resource out of excavated soils: a case study in the Paris Region

The material inscription of soil flows has become a public issue in the Paris Region as massive excavations are taking place due to large-scale urban works. In this context, various projects are emerging that propose to turn this waste into a resource. This chapter specifically focuses on the ones that aim at transforming excavated soils into ‘raw earth’ building materials. Such projects are conceived as contributing to the infrastructuring of a metabolic pathway, as defined by Pierre Desvaux, that consists of connecting excavation sites to building sites. Inspired by the sociology of translation, the making of a resource is problematised as articulating the potential roles of both soils and humans. By following soils among different urban actors, infrastructuring this metabolic pathway thus appears as much associated with a circulation and transformation of materials as with that of knowledge and material practices.