Definition of nearly zero-energy building requirements based on a large building sample

According to the recast of the Energy Performance Building Directive, Member States must give an exact definition for nearly zero-energy buildings to be introduced from 2018/2020. The requirement system stipulating the sustainable development of the building sector is usually based on the analysis of a few reference buildings, combining energy efficiency measures and HVAC systems. The risk of this method is that depending on the assumptions either the requirements do not provide sufficient incentives for energy saving measures and renewables or the requirements cannot be fulfilled with rational solutions in many cases.