The ratio between the energy services provided and the energy consumed. Something is more energy efficient if it delivers more services for the same energy input, or the same services for less energy input. [Source: IEA Glossary]
The 2002 Energy Performance in Buildings Directive required Member States to apply minimum requirements as regards the energy performance of new and existing buildings, ensure the certification of their energy performance and require the regular inspection of boilers and air conditioning systems in buildings. This was updated in 2010 by the EPBD recast. [Source: European Commission]
The calculated or measured amount of energy needed to meet the energy demand associated with a typical use of the buildings, which includes inter alia, energy used for heating, cooling, ventilation, hot water and lighting (EU). [Source: EPBD recast, 2010/31/EU]