Abstract
In line with the last European directives that boost actions for reducing the energy consumption in the resident ial sector, buildings refurbishment becomes key. On one hand, a deep building retrofit concerns actions aimed at reducing the building demands and the final energy consumption. In particular, the replacement of existing windows, the addition of an insulation layer on the external surfaces and the installation of a mechanical ventilation system with heat recovery (MVHR) help to drastically reduce the building demands. On the other hand, the installation of a system with improved performance can additionally decrease the final energy used for space heating and cooling (H&C) and Domestic Hot Water (DHW) preparation with respect to a tradition al system. Once the retrofit measures have acted on improving the energy efficiency of both building envelope and HVAC system, an additional contribution can be given by solar technologies integrated in the building.