BIM (Building Information Model and Modelling) is conceived as a working methodology based on interoperability and worksharing; this means that the data exchange is done without loss of information. The goal is the optimization of the building process characterized by a strong fragmentation and by a low efficiency in the data management during the different phases of design/survey, construction/renovation up to management and maintenance. Great deal of attention is paid to the definition of the as-built/as-is used; starting from as-built drawings it is possible to realize BIM models enriched with the essential contents for FM (Facility Management) such as technical specifications, photo/video, etc.