The development of district heating, which is part of French energy transition public policies, is promoted in particular as a way to recover waste heat that would otherwise be lost in the urban environment. The integration of these energy sources involves an important role for geographic and organisational proximity in the making of the energy provision service. Indeed, the system is based on the existence of a close and coordinated relationship between an urban energy system and activities that produce heat even though they are not linked to the energy provision service. Therefore, the situation relies on spatial and organisational coordination between traditionally separate activities.Building on work in industrial ecology and on the notions developed by the French school of proximity, this article analyses the role of proximity in urban structuring of heat networks supplied by waste heat in Marne-la-Vallée and Dunkirk in France. From this empirical analysis, it is demonstrated that, even though proximity is necessary to initiate the heat exchange, it cannot explain in itself the evolution of the network. In particular, the uncertainties that the activities are facing and local territorial dynamics play an important part in the decisions taken by the actors involved in the networked system, the latter appearing less stable in time than conventional energy networks.