A new method is introduced which combines a multicriterial evolutionary optimiser for structural optimisation with a code for the operational optimisation and simulation of energy supply systems. For the communication between the structural optimiser and the simulator the communal supply concepts are mathematically modelled using a superstructure, which is entered via drag and drop in a graphical user interface. The method is applied to the practical situation of an urban area. The resulting Pareto front and potentials for cost reduction and primary energy savings are discussed. (C) 2007 Elsevier Ltd. All rights reserved.