BIM Modelling of Ancient Buildings

In the last years, new procedures on design and management of constructions, based on 3D standardised models of building elements, have been proposed. It’s the case of Building Information Modelling (BIM) applications, that, differently from CAD ones, allow to work with libraries of 3D parametrical objects (smart objects) describing geometric, structural and material properties of building elements. This methodology is based on the Industry Foundation Classes (IFC) model, that represents a global standard for the building data exchange. Initially used for the design of new architectures, BIM methodology has been even more considered also for the management and the conservation of historical buildings, thanks to the possibilities of implementation of semantic information of 3D objects, guaranteed by the connection with the external database. At the same time, the lack of regular surfaces and standardised objects are relevant problems that nowadays strongly limit the use of BIM for Cultural Heritage (CH). Anyway, in recent times, the study of parameterised objects has opened new perspectives for BIM applications on historical buildings (HBIM). The present work shows the last achievements on this topic, focusing the problems derived from the application of BIM methodology to CH. In fact, the irregular shape of ancient architectural components, the wide variety of architectural languages that characterise historical buildings, the presence, sometimes, of different stratifications, are clear examples of the difficulties of implementing HBIM methodology for CH.