New research by CSIRO says Australian homes are now as much as 50 percent tighter than those tested in 2015, keeping energy bills down and indoor air quality better.
A recent report by the country's national science agency, CSIRO, has shown that modern Australian homes are a great deal more energy-efficient than they had previously been. New homes are up to 50% more airtight than those built in 2015, which holds positive implications for energy savings, comfort, and healthier indoor air quality.
It is the quality a building possesses that inhibits unintentional air flow, hindering air from going inside a house from the outside or escaping from indoors. Homes that are tight expend lesser energy; hence, their bills are low and they ensure comfort by improving the quality of indoor air. Poor airtightness tends to increase draughts flow in a way that could raise the energy bills by about 20% percent. On the other hand, houses that are sealed up too tight with no appropriate ventilation invite condensation, mould, and health problems associated with high levels of carbon dioxide and carbon monoxide, such as headaches and nausea.
In this, 233 newly built homes ranging from apartments to detached houses in Melbourne, Sydney, Canberra, Brisbane, and Adelaide were tested. Those homes that were to be made airtight, specifically, were excluded in this research. Still, the results were quite promising compared to the international standards, though certain areas needed improvement.
The study, headed by Senior Experimental Scientist Michael Ambrose, utilized a blower door test-a device for measuring air leakage rates-which also indicated the exact points where the most significant leakages were occurring. Among the more common problem areas were bathroom fans, sliding doors, and bad or non-existent seals around the doors. The study also discovered that some apartments were too tight, which leads to performance and health problems unless there is controlled ventilation.
Ambrose also added that most of these issues are relatively simple to address and fairly inexpensive to rectify, especially if caught at the construction stage. He outlined a few proposed changes he would like to see to the Australian building codes, including:
- establishing air tightness standards in the National Construction Code (NCC)
- requiring controlled ventilation in new buildings, particularly apartments to reduce indoor pollutants and moisture
- making air barriers, such as building wraps mandatory in all new residences
- providing on-site training and educational resources to connect builders with cost-effective solutions that improve building performance
The air tightness of the homes was also seen to reflect predicted levels using NatHERS - a Nationwide House Energy Rating Scheme that calculates the energy efficiency of a dwelling. This provides a good level of confidence in the accuracy of NatHERS ratings and places in context the additional information about air tightness on energy rating certificates.
In other words, the study finds very strong success in terms of the energy performance in new homes across Australia. This is because better energy efficiency and indoor comfort are characteristic of more airtight designs.