Building Energy Rating Scheme (BERS) is a highly sophisticated computer program, the brainchild of Dr Holger Willrath, one of Australia’s if not the world’s most knowledgeable expert on building energy efficiency. Dr Willrath is the director of Solar Logic.

BERS works by calculating how much heat (energy) enters or exits a building through all of its elements such as windows, roof, walls, floor etc, taking into account the climate and the geographic position of the dwelling anywhere in Australia (this is simply done using the BERS screen shown at right), the width of the eaves, the alignment relative to true north, and even the colour of the building, and much more, for every single hour of the year! It then works out how much energy would be needed to combat the excess gains and/or losses so as to maintain the building within a specified comfort band determined by the climatic zoning.  This program uses a very powerful 'engine' conceived by CSIRO called Chenath, and we use it to fine tune design elements such as windows, eaves and thermal mass properties until an optimum result is achieved.  Elements such as the colour of the dwelling, what materials the house is built of, what sort of window frames are used, whether curtains cover the windows and what type, what sort of glazing is used in those windows, and of course how much and what type of insulation is included in the roof/ceiling and walls, all need to be inputed along with the all important north point to arrive at the desired result.  BERS leaves no stone unturned.

BERS then calculates, for every single hour of the year, how much sun (solar energy) enters through the windows, how much heat enters or exits the house through those windows, the roof, the walls etc. The program can predict the temperature inside the building in any of six zones selected by the operator, and calculates how much energy would be required to heat the home when it's too cold, and how much to air condition it when it's too hot. The lower the energy required, the better the star rating.