_State of the art integrated urban energy systems design_ The design of energy systems concerns the definition of the equipments, their sizes their interconnections and the corresponding operating conditions. State of the art methods typically use mathematical programming techniques to solve the problem,. The method may combine mixed integer linear programming with multi-objective optimisation or Montecarlo simulation . One of the most important difficulty to be adressed is the problem size reduction: This can be done by choosing the appropriate time discretisation using typical days and using clustering techniques to identify the appropriate scope of the geographical zones . The geolocalisation of the demand and the resources as proposed by is an important part of the problem since there is a need to identify the existing building stock and to model the temperature levels that are required by the buildings. The use of heat cascade concepts inherited from the process integration techniques in the industry allows engineers to model the heat recovery and the proper integration taking into account the quality of the energy (exergy). Such models have in addition been adapted to account for the optimal predictive management of the storage systems that has to be considered together with the system design. The assessment of the system is typically based on technico-economic assessment. The use of multi-objective optimisation allows one to use alternative objective function like the exergy or Life cycle environmental assessment criteria . Optimisation based approaches have been used for assessing the integration of the geothermal resources, being for the heat pumping applications in the district heating , or the deep geothermal. One of the challenge in the field of the system design is to account for the future evolution of building stock considering the development of the infrastructure to be compatible not only with the present needs but also with the future needs. In addition, optimisation based methods need a definition of the objective function that is compatible with the socio-economic conditions and the criteria that are used to take the decision in the urban planning.