Energy Performance Certificate of building and confidence interval in assessment: an Italian case study

The Directive 2002/91/CE introduced the Energy Performance Certificate (EPC), as energy policy tool. The aim is to inform building owners and purchasers about the energy performance (and energy costs) of the building. The EPCs represent a specific energy policy tool orienting the building sector and retail market toward more energy efficient buildings. The effectiveness of the EPC depends on two factors: - The accuracy of energy performance evaluation, made by independent experts; - The capability of the energy efficiency classification and of the energy performance scaling to control the energy index fluctuations. The paper presents results of a case study performed in Italy. Here, 162 independent energy performance assessors have studied the same building. The results reveal software misunderstanding cause confidence intervals and that the energy performance classification ranks are able to tolerate the fluctuation of energy indices. The example was chosen in accordance with the legislation of the Emilia- Romagna Region on Energy Efficiency of Buildings. Thermo-economic evaluations related to building and energy labelling are illustrated and commented on, as the EPC, which is an energy policy tool for the retail market and building sector.