A 6 star energy rating involves using a simple computer modelling tool such as FirstRate5. First, you need to model the geometry of a house in two dimensions (floor plan). Then, you need and apply insulation, glazing performance values, and shading from adjacent elements. After entering several other parameters, the software calculates the area-adjusted heating & cooling demand of a house/apartment. Finally, the software converts the annual energy demand into a NatHERS star band of between 0 and 10. Under NCC 2019, if your dwelling achieves a 6 star rating or more, then you have could obtain a NatHERS Certificate.
