Improving energy ratings

ExACT's services will help you achieve compliance with an approved energy rating and at the same time providing you with our recommendations for designing for different Australian climates and advising on simple strategies, thus enabling you to potentially achieve a higher energy rating.

Design to improve energy ratings

Design for climate

One way to increase star ratings is to design for your climate zone.

Each climate zone in Australia has different design and construction requirements to achieve human comfort, using local conditions for passive heating and cooling, (cross flow ventilation, keep sun in, keep sun out, ordinations of buildings) to keep energy costs to a min.

There are 69 climate zones in Australia, some are cold and some are hot, some have a large diurnal temperature difference between night and day, these climates zones benefit some thermal mass to store any heat gain and cross flow ventilation at night to cool the house down. 

Orientation, can take advantage of solar heat gains in winter if living areas are facing to the northern side in the southern areas of Australia, to take advantage of the exposure to the sun, and in summer be shaded by eaves and shading screens.

You can achieve 6 stars a variety of ways. Most likely increased insulation to roof, walls and suspended floors will be required. Improved glazing may not be necessary if other elements are good – e.g. Orientation, insulation, and appropriate shading, climate zone – however, many homes will require improve glazing or low emissivity glazing to achieve 6 stars. 

All homes are designated in one of the 69 Climate zone in Australia, which is dependent on their post code. The FirstRate5 software then knows where your building is within Australia and what direction it faces and is built to the plans supplied, it will give star a star rating. Some climate zones require more insulation to the ceiling and walls, some require less, some require upgraded glass (double glazed/low emissivity) that prevents solar heat gain from entering certain rooms & some require different external roof colours to achieve 6 star compliance.

Strategies that minimise heating and cooling

ExACT recommends strategies, such as the selected list below, to help improve your energy rating.

Thermal Mass

Thermal mass helps reduce the heat in summer by absorbing and storing on and storing during the day, thus the interior does not warm up as much. At night time it gives up this heat which is, with the help of cross flow ventilation, carried out of the building.


When eaves are designed for climate zones they protect the windows from solar heat gains (SHGC) in the summer, but allow solar heat grains through the window for living areas that are facing north in the cooler months. Eaves are used to protect window areas from sunlight in summer when the sun is high in the sky, but let the sun shine through the windows in winter when the warming effect of the sun is desired.


Insulation reduces the heat flow in and out of the building in both summer and winter, allowing the owner to keep heat in, or out of the building improving the improving the energy costs of a building.


Trees can provide shading to windows on the east and west side of the building protecting the window areas that cannot be shaded by e.g. eaves because the sun is very low in the sky. Trees may also alter the strength and direction of the wind conditions around a building and depending on the location either positively or negatively support other passive measure such as ventilation

Sealing your house

Sealing your house is one of the easy ways to save on energy costs. Air leakage contributes up to 25% on energy costs, with new homes eight air changes per hour and up, where older homes up to 30 air changes per hour, reducing air leakage can save hundreds of dollars with very little cost to improve.