Shading and layout influence on flats energy performance of an apartment building

Giving the need for environment protection and energy need reduction, especially in the building sector, it is important to clearly understand what influences, and to what extent, buildings’ energy performance. In this work, an apartment building has been considered, and the influence of shadings and of flats layout on the energy performance ratings are evaluated. The case study is a building of the ‘90s, which has been demolished and re-built (2016) according to the actual energy requirements. For each of the 16 flats of the building, the energy certificate has been retrieved in the two configurations: before and after reconstruction. From the analysis of the specific energy consumption, and of their components (i.e. energy need for ventilation, transmission losses, solar gains), in the two configurations, a comparison amongst the flats has been drawn. Results show that the apartment layout influences the solar gains, but this influence (in percentage) is higher in the “ex-ante” configuration than in the “ex-post”. Similarly, the energy gains are more relevant in the “ex-post” configuration, in which some apartments, although having higher dispersing surface, result to be more efficient due to their favourable exposition.