Zero Energy Buildings: A Critical Look at the Definition; Preprint

A net zero-energy building (ZEB) is a residential or commercial building with greatly reduced energy needs through efficiency gains such that the balance of energy needs can be supplied with renewable technologies. Despite the excitement over the phrase 'zero energy,' we lack a common definition, or even a common understanding, of what it means. In this paper, we use a sample of currentgeneration low-energy buildings to explore the concept of zero energy: what it means, why a clear and measurable definition is needed, and how we have progressed toward the ZEB goal.