The definition was revised to exclude emissions produced by unregulated (plug) loads. This is mainly because of the nature of such loads, which are unpredictable and can vary greatly from property to property. If these loads were to be used, the target would be unattainable in many sites (due to cost or space restrictions). In the future, when more advanced systems will be available, these loads may be included within the definition. This change is aligned with the EU trend, where most of the Member States have not included unregulated loads in their Nearly Zero Energy Buildings definitions.