Creating a Net Zero Energy House – A Case Study

The CRC for Low Carbon Living ran a study in 2019 on the changes required to take a typical project style home to a Net Zero Energy House and the costing of these. Different scenarios across Australia were modelled, including one in Perth. The studies included the following changes and assessed which ones had the most impact on reducing energy consumption:


  • -Modifying windows & adding security screens for cross flow ventilation
  • -Using Low E glazing to select sliding doors and windows
  • -Addition of insulation
  • -Ceiling fans in bedrooms
  • -A split AC system
  • -Heat pump hot water system
  • -Induction stove
  • -LED lights
  • -A kill switch for appliances on standby


The Perth home energy usage was modelled on a two storey 3 bedroom, 2 bathroom home with 4 occupants. To satisfy the home’s energy needs just over 5kWh/yr was required, modelling this with a worst case occupancy scenario they found a 4kW PV system was more than sufficient to achieve a status of net zero energy. Within the series of changes made, the one that had the biggest single impact was in water heating – (using a heat pump rather than instant gas heater), followed by the addition of Low-E glazing, and then in heating and cooling (using a combination of ceiling fans and a split AC system). A cost estimation was done for each of the changes to assess their payback period and financial viability.


To read more about the study, head here and here for the Mainstreaming Net Zero Energy Housing – Design Review Report & Cost Analysis Report. This is a great paper that can demonstrate to you the tangible outcomes of more sustainable design decisions and is a great introduction to ideas that you can include in your new home. With many years’ experience in designing all types of sustainable homes, we can work with you to incorporate a whole range of sustainable choices into your home. The uniqueness of each home will impact what measures are most feasible for you, in both the sustainability outcome and the cost effectiveness. We can advise on what will give you the most bang for your buck, depending on your home, your lifestyle, and if you have your mind set on any particular sustainability areas. Get in touch with us today to discuss how you can have your very own Net Zero Energy Home – or one that is at least partway there!