The energy performance improvement of historic buildings and their environmental sustainability assessment

The changes in present world oblige the scientific community working on Cultural Heritage to face the every day more urgent challenges of “sustainability”. This concept refers to a very broad horizon, touching various spheres: cultural, economic, social, environmental, before the purely technical and energetic one; the terms deals, in fact, with a sustainable process of conservation, renovation, reuse and management of historical architecture, where the assessment methods could play a key role even in the early stage process. The assessment of environmental sustainability of historical buildings may help to recognize potential ways of enhancement. This is the main content of the article, showing results of a multi-disciplinary research on a representative case study, the huge historical complex of the Albergo dei Povery of Genoa (XVII-XIX Century), which will be completely restored and reused as a university campus. To highlight the increasing value of a smart renovation, the sustainability of the energy solutions has been analysed verifying how a good rating can be obtained, within the early design process, in the energy performance sectors. The results allow to show that better results can be reached in the environmental sustainability certification by means of added actions not strictly needed, but allowed. A proposal of a methodological approach to the sustainability evaluation for historic building renovation is the main result of the investigation. A relevant step of the assessment is represented by the comparison of the obtained scores with calculated reference scores that not correspond to the absolute maximum values. This approach helps to individuate the fields in which higher global scores can be reached by planning smart renovation actions. The results allow also to put in evidence some aspects of the procedure application that can be improved for a more appropriate use of sustainability rating systems for this particular kind of heritage.