This study analyses the energy consumption of a social housing built in the 80′s. This typology is widely diffused in the building stock of Rome and of the city’s suburbs and for this its improvement represents a dutiful effort for the Italian national scene, where the energy efficiency of public social housing is a major concern. Public funding is significantly reduced compared to the past and the conditions of the buildings are deteriorating over time, resulting in an increase in energy consumption for air conditioning and in indoor comfort conditions very far from the standards. Often it is also very difficult to act on the passive system, with the insertion of a thermal insulation, as well as inside the apartments, with the replacement of terminal units. For this reason a good way is to evaluate the possibility of modifying the thermal energy generation system, preserving as much as possible the distribution and supply system inside the apartments. In general, where the boiler is not obsolescent, the idea is to propose a hybrid generation system with the inclusion of a heat pump (HHP), which could be implemented with renewable energy equipment, properly installed in the building. The results show that a hybrid system can lower the primary energy consumption up to 28%, thus allowing the employment of renewable energies within the social housing building stock.