6 Star rating involves using a simple computer energy modelling tool such as FirstRate5 to model the geometry of a house in two dimensions (floor plan) and apply insulation, glazing performance values, and shading from adjacent elements to calculate the area-adjusted heating & cooling demand of a house/apartment. The annual energy demand of the building is then converted into a star rating between 0 and 10 stars. If your house/apartment achieves 6 stars or more, then you have could obtain a council-ready energy compliance certificate.