Our homes are becoming more airtight, thus more energy efficient!
For many years Australian homes were some of the worst performing in the OECD in terms of uncontrolled air leakage, which has such a detrimental impact on energy efficiency.
A recent CSIRO study, however, shows that standards are improving. Over the past 9 years, new homes in Australia are now 50% more airtight.
For the past 14 years we have been on the leading edge of this movement by pressure testing all our homes we’ve built to quantify the level of airtightness.
During much of this time, we have aimed for an airtightness level of around 5 ACH (Air Changes per Hour @ 50pa) as this has long been considered the sweet spot between performance and cost effectiveness.
The NCC (National Construction Code) has now introduced a requirement for mechanical ventilation to be installed on homes that have an airtightness level below 5 ACH.
As we commonly achieve airtightness levels of 4ACH or below, we are now installing a mechanical ventilation system as a standard.
Below is a summary of some of the available options:
A system like this typically costs around $25,000.
This is a simplified HRVS by Mitsubishi that is around half the price at around $12,000.
To adequately service an entire house you would require a number of these paired fans which cost around $10,000 to $14,000.