Design optioneering for the energy retrofitting of public residential buildings

The paper reports on the first findings of an ongoing research shared by the Politecnico di Milano and the Department of Civil and Environmental Engineering and Architecture of the University of Cagliari. The research focuses on the development of a BIM (Building Information Modelling) workflow aimed at the formalization of the knowledge process and the evaluation of alternative scenarios for the retrofitting of public residential buildings. The case study is a group of public owned buildings located in a small town in the south of Sardinia. The buildings have already been studied by RELS (Renovation Energetique des Logements) project, financed by ENPI European program in 2011. It was focused on the use of the “cost optimality” methodology to evaluate alternative scenarios of energy retrofitting measures. The paper shows how the Building Information Modelling can support the above methodology to manage information and to integrate all the associated processes. Starting from the geometrical and constructive features of the case study and from its energy and use profile, the work focuses on the construction of the informative model of the building. The model is conceived in order to structure all the gathered information and to formulate solutions of intervention. The work ends with an experimental analysis of different scenarios for the energy retrofit and the results in terms of cost optimality are compared with the ones achieved by RELS project.