The calculated energy balance is done using all the elements above and formulating them using the PHPP (Passive House Planning Package). This package evaluates the performance of each element, whether it is the external fabric or the ventilation system and provides the overall Heat Demand that the building is using at that time. As a Passive House requires a maximum Heat Demand of 15kWh/(m²a). Using the package, elements can be adjusted to get to this figure; for example if the figure is at 16, an increase in insulation thickness to some element of the build could push this down to below the 15 level required.
The planning package gives a very detailed breakdown of the building fabric and allows full control and manipulation of the construction to get to the end result of 15kWh/(m²a).
