Relazione. Convegno Geores 2017. GEOMATICS & RESTORATION – Conservation of Cultural Heritage in the Digital Era, Firenze, 22-24 Maggio. Titolo dell’intervento: Critical Issues and key points from the survey to the creation of the historical building information model: the case of Santo Stefano Basilica. (C. Castagnetti, M. Dubbini, R. Rivola; P. C. Ricci, M. Agnoletti, M. Giannini, A Capra).

The new era of designing in architecture and civil engineering applications lies in the Building Information Modeling (BIM) approach, based on a 3D geometric model including a 3D database. This is easier for new constructions whereas, when dealing with existing buildings, the creation of the BIM is based on the accurate knowledge of the as-built construction. Such a condition is allowed by a 3D survey, often carried out with laser scanning technology or modern photogrammetry, which are able to guarantee an adequate points cloud in terms of resolution and completeness by balancing both time consuming and costs with respect to the request of final accuracy. The BIM approach for existing buildings and even more for historical buildings is not yet a well known and deeply discussed process. There are still several choices to be addressed in the process from the survey to the model and critical issues to be discussed in the modeling step, particularly when dealing with unconventional elements such as deformed geometries or historical elements.