Annual Thermal Demand for Australian Residential Buildings

For Australian residential projects, there is a handy resource for estimating what the thermal performance of the building is to input into the Services of your functions. This is particularly important for when you are using eTool energy templates that calculate the operational energy for HVAC for you as the template will have expressions that reference this information.

If you are modelling a Business As Usual design, you’ll need to reference the Australian National Construction Code to find out what the thermal performance requirement is for your project. Usually, the NCC will refer to the NatHERS star rating for the thermal performance.

Once you’ve determined what the minimum requirement is, you can use the NatHERS Climate Zone Map to find out which climate zone is applicable for your project. For the example below, the climate zone for this location is Climate Zone 22.

With this information, you can then refer to the NatHERS star bands to find out what the expected total annual thermal demand in MJ/m2 is for a building in that location at the different star ratings. For this example below, the NCC minimum requirement is 6 Stars so our total thermal demand is 133MJ/m2.

Note that before we enter this figure into eTool, the thermal demand is split between heating & cooling. Therefore, the 133MJ/m2 will need to be split between the two. You will need to do some research to find some references for what the typical split is for a residential building in your location.


  1. Clare5136

    Hi Fei,
    So I can check if I understand this correctly, this entry then is automatically used to calculate the operational energy?
    If I don’t enter in any air conditioning systems (i.e. to get COP), is it effectively ignored/not used?

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