The integration between heat pumps and renewable energy sources (i.e., solar energy) is a promising and recognised technology to reduce primary energy consumption for building cooling/heating. This paper contributes to the existing discussion concerning field performances of multifunctional solar-assisted heat pumps, for cooling/heating applications, and for the production of domestic hot water. The proposed system has been tested experimentally, in a detached house in Milan, to obtain the seasonal performances; in particular, based on experimental observations, energy and exergy analyses have been formulated and applied to the heat pump control volume and to the whole system control volume. The results of the energy analysis have demonstrated that the system was able to maintain high efficiency in the different seasons. The exergy efficiencies of the heat pump and of the whole system were similar in their values, thus suggesting that the heat pump control volume is the location where most of the exergy losses occur, thus pointing out where the future research activities should focus to improve the performance of the proposed system.