Geometric survey data and historical sources interpretation for hbim process: The case of mantua cathedral facade

Planned conservation approach requires a sustained, long-Term action to better manage the cultural heritage assets during their life cycle. Together with programmed conservation and local interventions, there is a large amount of information related to the building; it emerges the need for an appropriate tool in which to store all data. Historic Building Information Modelling (HBIM) can be an appropriate way to address this issue. In this context, the lack of automatic tools (to speed up the project) and the need for data interpretation in the process are noticeable, especially for cultural heritage items. In this paper we present a practical case study. Starting from an integrated survey of Mantua Cathedral (located in Northern Italy) we developed a HBIM model of its façade. Particular emphasis is given to data interpretation both from geometrical survey and from historical sources. The resulting model is consistent and coherent with reality. As a result, we state that the development of a HBIM model is not an automatized process. In the process, from the survey to the final model, there is the need for a deep knowledge and a deep understanding of the building, not only in term of geometrical survey but also of its historical phases, its changes in time, its materials and the construction techniques. HBIM can be a useful instrument for planned conservation, which strongly requires a coherent model to be effective and useful. A proper model, working as an integrated archive, can increase the effectiveness of planned conservation.