This project focuses on the urban renewal of (delta) metropolises and concentrates on the question how to design resilient, durable (subsurface) infrastructure in urban renewal projects using parameters of the natural system – linking in an efficient way (a) water cycle, (b) soil and subsurface conditions, (c) soil improvement technology, and (d) opportunities in urban renewal (e.g. urban growth or shrinkage). The subsurface is the technical space, the engine room of a city, housing the vital functions of water, electricity, sewers and drainage, but also housing the natural system that is crucial for a stable, green, healthy and livable city. Especially the effects of climate change, the boosts for an energy transition and the fact that there are less financial mean makes the intelligent use of the subsurface more important. This prublication reprots on the explorative method to get insight and design methods for the urban renewal of (delta) metropolises where resilient, durable (subsurface) infrastructure is carefully balanced out with parameters of the natural system. The question “how can the different technological artefacts in the subsurface be synchronized offering more space and adding to a better urban quality?” is answered by working with the municipality in an interdisciplinary explorative research and design. The exploration was framed by co-creation in workshops and use of provocative scenario's; later a more precise elaboration of these results were done in the working group.