The term ‘zero energy’ sounds contradictory. We need energy to produce materials, then construct, operate and renovate or demolish buildings. Once a building is occupied, we need energy for heating, cooling, hot water, cooking, and we use electricity for a myriad of other energy services. And there is a temporal dimension – to produce energy at the time when it is needed.
‘Zero energy’ in its current use does not mean ‘compensating all energy uses related to the building, over its entire lifecycle, at the time when energy is needed’.
The term works well as a commercial label. For regulation, it lacks precision.