The application of the Building Information Modelling (BIM) process to Built Heritage (HBIM) is a growing practice in processes and activities aimed at the investigation, documentation, and conservation of architectural heritage. However, it still raises some questions, such as the compatibility between the formalisation of information in the BIM model; and what limitations are inherent in current software implementations to establish a connection with external resources. On this basis, this paper aims at reviewing which methods are currently experimented to improve the level of semantic enrichment and to extend the knowledge representation domain offered today by the most common BIM authoring tools in an HBIM process. The analysis distinguishes two approaches that differ in the role played by external databases and the objectives pursued. Conclusions were drawn highlighting common needs for overcoming technical and conceptual limitations imposed by the use of proprietary BIM authoring tools, and differences in application perspectives and effectiveness.