Transactions between energy producers and consumers are most often settled outside the urban project according to the usual rules of connection and operation of public energy networks. The economic optimisation then often leads to the use of exogenous energy, of fossil or fissile origin. Conversely, the energy community vision aims to anchor production and share it locally. Some urban development projects have the same objective. In this context, one may wonder if energy systems are designed in conjunction with the design of architecture and public spaces, and how energy sharing is considered within such projects. Considering the notion of urban project and socio-technical approaches, this chapter highlights the spatio-material interdependencies between energy and urbanistic designs before exploring the joint design processes (if any) of two urban projects aiming at in situ production and consumption of renewable energy: one in Freiburg, Switzerland, the other in La Motte-Servolex, France. The authors emphasise the need to think about the management of energy flows right from the start of the urban design phase, in other words, to establish the operating principles of one or more future energy communities within the perimeter of the urban project.