On the surface, this seems like a simple enough concept to implement for the average Australian home. However, it almost never achieved in practice, with Adelaide falling far behind the rest of Australia in energy efficient home construction.
Passive housing has become far more common in Europe and North America and builds upon their already superior building standards and laws.
While Australia overall is left behind on the world stage, some suppliers and builders have recognised how well built their houses are and there is a slow shift in the industry starting to appear, which is good news for some of the future Adelaide homeowners.
Insulation controls the energy transfer between the inside of your home and the outside climate. When a home is insufficiently insulated, or the insulation is poorly installed, it allows the heat or cold to pass through the walls, windows and roof and into your home.
In Australia, insulation is measured with an ‘R-value’, where the higher the R-Value, the better insulated a wall, roof or slab is. A new home in Australia typically uses ~R2.5 Batts in the wall frames and ~R5 insulation batts in the roof.
On paper, these numbers are designed to be practical and energy efficient for our climate zone and help achieve a ‘6 Star’ Energy rating. However, the batts themselves are installed between timber studs, and a 10mm gap between the batts and the studs can decrease the effectiveness of the insulation by up to 40%.
As well as this, the timber studs themselves become a thermal bridge to the outside, allowing the heat or cold to pass more easily between your home and the climate outside
The above pictures, taken on a cold morning with a thermal lens, exhibit two homes: One built with a quality ICF product, with thermal mass sandwiched between continuous, unbroken, insulation and another, built with timber studs and insulation in between.
It becomes quite clear to see the heat energy leaking through the frames and to the outside. Passive housing focuses on not just achieving appropriate R-Values, but minimising or eliminating insulation gaps and thermal bridging.
The Passive house approach combines well-insulated roof area and walls, with high quality double and triple glazing and a building practice that minimises or eliminates thermal bridging. This ensures that your home in the city of Adelaide, is both designed and built to withstand the hot and cold outside temperatures, creating a home that is warm in winter, cool in summer, naturally.
Furthermore, this home building approach will be a great relief for the homeowners with huge energy savings to tackle the high electricity charges in South Australia.