Refurbishment of a historic building in the center of Turin. Study of technical systems solutions and energy performance assessment through the LEED® certification protocol

The certification standards of building sustainability are proving to be more and more a fundamental guarantee of performance and accordingly they can make a project attractive to investors. A widely recognized protocol at international level is LEED®, with its various forms and translations in different contexts. Within the various versions of the protocol, the issue of energy is the most important in terms of score: for this reason it is widely considered by the designers who aspire to certification. A great challenge of LEED protocol in Italy is its contextualization in a scenario characterized by an extreme fragmentation of energy legislation and with a large number of historic buildings. In many cases such buildings require refurbishing, but also the architectural elements must be preserved for their special historical and artistic value. The study concerns the emblematic case of a historic building used as a research and teaching university, located in Turin. This building has been subject to an envelope and technical systems refurbishment, designed according to evaluation criteria addressed to sustainability certification. The building is candidate to become a case study for the new protocol for historic buildings (GBC Historic BuildingTM), currently being developed by the Green Building Council Italy. It is subjected to protection constraints for its special cultural interest, and, accordingly, the systems design choices are oriented to the preservation of the architectural elements. During the design activities a particular attention was given to the assessment of energy performance, by adopting two calculation models: quasi-stationary and dynamic. The comparison of the two methods allowed a series of considerations both about the design choices, and about the applicability of the different calculation models.