The decision to make a wall like that is due to the fact the designer wanted to reduce to minimum the energy losses in winter and this solution allows to have really low consumption of energy. The transmittance of the walls is of 0.107 W/m2K, one third lower than the limit imposed to new construction for the 2019. In addition, the slabs are well isolated to reduce the vertical heat losses, using a layer of 10cm of EPS, having a light construction with high thermal and acoustic performances.
The windows have a PVC frame to reduce thermal losses and corrosion; they are characterized by a triple layer of glass, also good from a thermal point of view. This kind of glass allows the solar light to enter the building because of the big area of the windows, it is important from a thermal point of view because there are useful solar gains in winter and the triple layer stops the heat to flow from inside to outside. In summer, the sun is higher than in winter, so we have balconies with also the function of overhangs to reduce the solar gains. The total transmittance of the windows is 0.71 W/m2K.
Analyzing the energy balance of the building is possible to say that the heat plant is almost unnecessary due to the solar gains and how they are managed. In the southern part are installed a series of horizontal fixed shading system on the balconies and on the windows to avoid overheating during summer.