A zero energy building (ZEB) or net zero energy building
is a general term applied to a building with a net energy consumption
of zero over a typical year. Zero energy buildings are gaining
considerable interest as a means to cut greenhouse gas emissions and
conserve energy. Buildings use 40% of the total energy in the US and European Union.
This can be measured in different ways (relating to cost, energy, or
carbon emissions) and, irrespective of the definition used, different
views are taken on the relative importance of energy generation and
energy conservation to achieve energy balance.