What’s the difference between an NZEB and a passive house?
The terms passive house and Nearly Zero Energy Building (NZEB) both refer to designing buildings that require very little energy to run comfortably, i.e. low energy bills.
In the context of house building, a big difference is that NZEB is specifically referred to in Part L of the ROI building regulations, defined as a building with a very high energy performance that gets the very low amount of energy it still requires mostly from renewable sources, on site or nearby.
In practice, this means building a house that retains heat very well and installing some form of renewable system(s), usually in the form of a heat pump or solar panels.