Energy performance of the building is a set of parameters that determine the energy demand of a building for its use. It includes, among others, energy consumption for heating, cooling, ventilation, hot water preparation and lighting. It is expressed in terms of energy indices. Such as EP (non-renewable primary energy demand) and EU (useful energy demand). It is determined on the basis of the properties of the building envelope, the installation systems and the operating conditions.
The energy performance of a building forms the basis for an energy performance certificate and an assessment of the energy efficiency of the building.
In Poland, an energy performance certificate is required in various situations. Among others, when selling or rental of a building and for newly constructed buildings being put into use. The certificate is valid for 10 years. Unless, before this period expires, significant changes are made to the building that affect its energy performance, such as thermo-modernisation or replacement of the heating system.
