Prototyping a digital twin. A case study of a "U-shaped" military building

The aim of the article is to cover part of the issues related to develop a process aimed at defining some essential step to correctly plan a ‘smart district’ that could dispatch energy produced in excess to the district’s other buildings. The first step has been to search for a type of building with very similar characteristics, such as geometry, zones, with the obvious variant of the geographic localization and thermal behaviour, on the other hand, a certain computational approach has to be set, in order to achieve a further replicable and scalable approach to a small-scale urban building energy modelling (UBEM). Focusing on various characteristics, a standard ‘U-shaped’ building, belonging to a ‘military district’ in a southern city of Italy (Bari), has been chosen as a case study. In order to obtain energy informa- tion, the authors have started investigating first the basic components of the building through measures, thermal imaging, heat flux sensor, borescope, secondly a BIM model has been set and then enhanced to a Building Energy Model (BEM) trying to replicate the energy behaviour of the case study as close as possible. Although many technological innovations are emerging, the ‘BIM to BEM process’ and the ‘BEM analysis process’ itself still depends on too many variables and results on several experiments conducted showed a variation of up 26%, that probably could be improved only by a rigorous/hybrid workflow through a digital twin.