Considering that this zero-energy housing validation complex is the first one to be ever built in Korea, we should place utmost significance on the suggestion and establishment of the globally applied concepts of the zero energy housing and net zero energy housing.
Zero-energy housing and new zero-energy housing refer to self-reliant building. Net-zero energy housing can be defined as a type of housing that is connected with an external grid and for which the source energy is 0 in the energy balance sheet of used energy and generated energy.
In particular, not only the EU but also the National Renewable Energy Laboratory (NREL) under the Department of Energy (DOE) of the US emphasizes the definition related to the use of renewable energy than on the generation of energy. In addition, renewable energy can be divided into four different types depending on whether is it supplied on-site or off-site.
As defined by Torcellini at NREL in 2006, the definition of net zero can be subdivided into net-zero site energy, net-zero source energy, net-zero energy emission, and net-zero energy cost.