Future power systems require a change from a "vertical" to a "horizontal" structure, in which the customer plays a central role. As buildings represent a substantial aggregation of energy consumption, the intertwined operation of the future power grid and the built environment is crucial to achieve energy efficiency and sustainable goals. This transition towards a so-called smart grid (SG) requires advanced building energy management systems (BEMS) to cope with the highly complex interaction between two environments. This paper proposes an agent-based approach to optimize the inter-operation of the SG–BEMS framework. Furthermore a computational intelligence technique, i.e. Particle Swarm Optimization (PSO), is used to maximize both comfort ...