The EC programs on the energy efficiency are bound and specific in the field of energy performance of buildings, it refers to the characteristics of the building and to the use of renewable sources. In this work, starting from a real case, and represented from the Italian Pavilion of EXPO 2015, it analysed the services of a nearly Zero Energy Building (nZEB), characterised by a careful design of the building, by a very efficient installation systems and by a large use of renewable sources. The aim is to focus on the energy performance of the building, pointing to some features of the building, highlighting some critical issues related to the existing legislation, providing suggestions for the improvement of legislation in the field of the energy efficiency of buildings which is constantly evolving in Italy and in Europe. This work has to represent the EXPO 2015 theme: "Feeding the planet, energy for life". (C) 2014 Elsevier B.V. All rights reserved.