In the last few decades, an increasing attention has been paid to the enhancement of energy performance and indoor comfort conditions of historical buildings, where the architectural heritage and artistic value do not allow typical retrofit intervention. The need to enhance the energy efficiency and environmental sustainability of historic buildings is addressed in this paper, through energy modeling and dynamic simulation of a real building with the integration of renewable energy plants for building heating and cooling. The pilot case study is “Palazzo Gallenga Stuart”, a historical university building located in Perugia, Italy. The energy performance of the building has been evaluated in order to reduce the building energy demand through the implementation of high-efficiency technologies in historic buildings. The increase of the energy efficiency of the building has been pursued through the improvement of the actual energy plants’ technology by introducing a more effective heat pump plant, in order to prevent the use of visually impacting external units on building historic façade.