This norm applies BENG, which is determined with NTA8800. It outlines a method which establishes the energetic quality of a building, based on its properties and facilities. However, practical experience indicates a mismatch between the actual energy intensity of a building, and the energy intensity that is determined according to the energetic qualities of a building based on the BENG calculation. Therefore, an instrument is required in addition to BENG which can be used for guiding towards the actual energy intensity of buildings. For this purpose, initiators TVVL and DGBC have developed WEii.
WEii is an acronym for the Dutch ‘’Werkelijke Energie Intensiteit Indicator’’, which is the actual energy intensity indicator. The WEii of a building is determined based on the measured, and thus actual, energy use and floorspace of a building. The applied unit of WEii is kWh per year per m2. WEii is constituted of a calculation protocol, a classification of building types and classes of energy intensity per building type. WENG, an acronym for the Dutch ‘’Werkelijk Energieneutrale Gebouw’’, meaning truly energy neutral building, and Paris Proof, a building that meets the requirements of the climate agreement, are two of the most ambitious of a total of seven classes of energy intensity. WEii provides a uniform and objective method to describe the actual energy intensity of a building. Using this unambiguous definition of the actual energy intensity allows for clear communication concerning the actual energy performance of buildings. WEii is not a commercial tool and is therefore available for free use.
The WEii protocol, the English version of which can be downloaded below, describes the background and prescribed use of the WEii calculation tool, as well as a classification of building types and classes of energy intensity per building type.