Social norms have a potential to contribute to advances in social intelligence. One approach to take this advantage in the design of virtual agents is the use of institutional models - a social reasoning framework which brings about social norms - in conjunction with classical AI techniques, to achieve the appropriate recognition of complex situations and provide guidance on the subsequent choice of adequate action(s) with norms. In this paper, we aim to show that the combination of an institution providing social reasoning and BDI agents providing individual reasoning, establishes a framework for socially intelligent behaviour by the interplay between: (i) the institution and Intelligent Virtual Agents (IVAs), and (ii) norms maintained by the institution and the mental states of IVAs. From an engineering point of view, the framework provides a separation of concerns because the BDI agent is augmented with the capacity to process social obligations, while the specification and verification of social structure resides in the institutional models. We illustrate our approach with two scenarios: one on queuing and another on inter-personal distance theory.