Having energy flexible buildings is a very important aspect to enable the application of smart demand side management strategies (DSM). DSM is getting more and more relevance in energy systems planning and operation due to the overall increasing energy demand. An energy flexible building is intended to be able to change, in a planned manner, the shape of its energy demand curve, electrical and thermal, while the comfort of the end-users is still guaranteed. The objective of this study is to develop a methodology that allows to classify buildings according to their potential to provide energy flexibility on the basis of their design features. Similarly to the energy performance label, this methodology aims to be a means to extend the energetic characterization of a building also to its energy demand management ability. In this paper the thermal energy demand of buildings (supplied by electrically driven devices, e.g. heat pumps) is mainly taken into account. A quantification method is introduced to estimate the thermal energy demand flexibility. Since the potential to manage the energy demand of a building is strongly influenced by dynamic boundary conditions, “test conditions” have been defined in order to make the method repeatable, not dependent on the specific operational conditions, but more on the design specifications. In this manner the evaluation takes into account only the intrinsic aspects of the building, identified by the construction characteristics and the type of distribution system for the heating and cooling apparatus. Different buildings typologies, representing the most common Italian residential buildings, are considered. Their models are simulated in TRNSYS. The results show a great potential as energy flexibility providers for the latest generation buildings (from 2006 onwards) with a good level of insulation and a radiant system served by a heat pump
