The paper analyzes the introduction of a photovoltaic system satisfying electric, space heating and cooling demand of an office building located in southern Italy. The electric load is due to an electric heat pump, used to satisfy space heating and cooling load, a pure electric demand (personal computers, printers, lighting, etc.) and an electric vehicle charged during working hours. Dynamic simulations to evaluate the energy and environmental performance of the analyzed system considering different photovoltaic peak powers (4.5-9.0 kW), electric vehicle distance per day (40-120 km) and charging mode is carried out. The solar based system shows primary energy saving and equivalent carbon dioxide emission reduction higher than 40% in comparison to the reference conventional system based on a natural gas fired boiler, an electric chiller and a diesel car. The results highlight that the solar energy system is more competitive when DC charging system is provided. (C) 2016 Elsevier Ltd. All rights reserved.