Il recladding di un edificio pubblico in clima mediterraneo

Most public buildings in Italy were built before the enforcement of any legislation regarding energy savings, thus they show very disappointing energy performance. Since the most recent European Directives drive towards a radical improvement of the energy quality of public buildings, it seems suitable to investigate appropriate strategies for a massive energy refurbishment of the public building stock in Italy. In this paper, the authors describe a retrofit solution for a building, situated in Southern Italy, that hosts the local Department of Civil Engineering and Architecture. The proposed intervention is mainly based on the improvement of the insulation level, and contemplates the use of terracotta tiles for the outer finish of the opaque envelope. The building has been modeled on DesignBuilder, and the dynamic thermal simulations have allowed the calculation of the overall energy needs for space heating and cooling, both for the current building and for the improved solution. The results show that there is great room for improvement, and that the building can also become a Net ZEB with the installation of a moderate surface of PV modules on the horizontal roof. On the other hand, the proposed solution may not be attractive under an economic perspective, because of a too high pay-back time of the investment. However, the same intervention would produce more encouraging results if the building was placed in Northern Italy. This suggests that the energy retrofit of public buildings in Italy must be attentively evaluated in relation to the climate, and that in warm regions it might be more interesting to rely on the renovation, monitoring and control of heating and electrical systems.

La proposta di riqualificazione energetica della sede del Dipartimento Ingegneria Civile e Architettura di Catania è diventata l’occasione per rinnovare l’immagine dell’edificio, che viene dotato di un leggero rivestimento in doghe di terracotta. I calcoli termici hanno tuttavia evidenziato che, in clima mediterraneo, il recladding di un edificio pubblico non sempre risulta un’operazione vantaggiosa, in quanto comporta lunghi tempi di recupero dell’investimento