Interoperability is the ability of two or more systems to exchange information. It is one of the pillars of BIM because the information contained in a BIM model needs to be exchanged to be useful. IFC is cited as the best option for achieving interoperability in Construction but, although several applications have been certified to be IFC-compliant, flawed exchanges are too common yet. Behind IFC, some other less known standards play an important role to make BIM interoperability a reality. Among them are IDM, MVD and IFD. This paper will briefly show how these standards take part in data exchange and discuss the reasons why AEC interoperability is still such an elusive goal.