In this paper, a district heating, cooling and power generation unit has been evaluated from the viewpoints of cost and CO2 emissions. The superstructure considered includes a solid oxide fuel cell and gas turbine (SOFC-GT) combined cycle, a compression heat pump, an absorption chiller, a compression chiller and an additional boiler. Both physical and costing modeling has been developed for evaluating the economics and environmental benefits associated with the design and the operation of several possible configurations for given heating and cooling requirements of small building clusters. The optimization process undertaken with a new multi-objective evolutionnary algorithm reveals the high potentional of CO2 emissions mitigation achievable with the implementation of advanced integrated energy systems within urban areas.