House Energy Ratings

Orientation - Your Home Technical Manual -

Good house orientation and an energy efficient house design can go a long way towards improving your lifestyle and reducing the running costs of your home. A house that is designed to retain the heat effectively in winter, and reduce the build up of heat in summer, has an energy-efficient thermal envelope.

Some of the easy ways that you can improve your thermal envelope and reduce energy consumption in your home are by;

  • increasing insulation;
  • installing windows that are properly sized and located to allow effective cross-ventilation;
  • double-glazing or Low E treatment of windows;
  • providing wide eaves or overhangs;
  • external blinds or awning; and
  • sealing gaps and cracks.

Energy efficiency in Victoria is typically measured by rating the dwelling using the FirstRate house energy rating program by the Victorian State Government. Every new house in Victoria must be built to comply with a minimum “6 Star Standard” as of May 2011.

To enable better interstate comparisons, a base case house was rated using the Accurate house energy rating software. Accurate is an energy modelling program accepted Australia wide.

It has been assumed that heating systems are to be gas ducted and cooling systems are to be electric ducted split systems as these are the most common systems installed in new homes in Victoria.

A standard new house in Victoria is 6 star rated in FirstRate, though Accurate may also be used. This acknowledges the benefits of building a new house and achieving higher energy efficiency standards, as opposed to moving to an existing dwelling requiring high levels of mechanical heating and cooling (higher living expenses). It also recognises that much of today’s housing stock does not meet today's requirements. These calculations are based on an average house size of a new dwelling being 226m2, which in the Melbourne climate zone expends 114MJ/m2/year. Changes in climate or dwelling size will affect results.

For more information please visit:

Black Balloons - Carbon use in Victoria

Sustainability Victoria

Building Green

Home owners must select a home energy rating that is achievable for their home, this can sometimes be supplied by the builder of their new home. If not then a Home Energy assessor will need to be contacted, Sustainability Victoria will be able to put the home owner in touch with a qualified assessor.