In this paper, a refurbishment process of a single family house in a North Italy town is considered by means of energy and exergy analyses. The building, located in Padova, a small town in Northern Italy, has two floors: two bedrooms, two bathrooms, a living room and a kitchen at the first floor, two bedrooms, one bathroom, a living room, at the second floor. The hourly energy needs for heating, cooling, and summer dehumidifying are evaluated by means of TRNSYS 17; the monthly energy needs for domestic hot water supply are evaluated according to UNI/TS 11300-2. The plant is composed of an air-to-water heat pump for heating and cooling, with PV cells designed to meet the whole electric energy use of the house, including lighting and domestic appliances. The hourly electric energy use for heating, cooling and dehumidifying is evaluated by considering the hourly energy need, the plant emission and regulation efficiency, the COP and EER data of the heat pump, given by the constructor, and the methods recommended by UNI/TS 11300-4 and UNI/TS 11300-3 to take into account the reduction of COP or EER due to intermittent operation.