• Net zero energy buildings level (NZEB) At this level, new low-energy technologies, some
promising but are not commercially available, are employed. System performance levels are all higher than those at the ECON level. For these building types, on-site electricity production from PV cells almost meets the demand of the whole buildings. This is the imaginary zero energy building created by using mathematical model. Energy consumption in this scenario is 55 kWh.m-2.Y-1. But when electricity from the roof top PV is accounted, the net consumption is 27 kWh.m-2.Y-1. Net zero energy buildings have been built for
demonstration in many countries including Australia, China, Malaysia, and Singapore.