Recent research conducted by CSIRO has highlighted the significance of air tightness in Australian homes. The study revealed that new homes in Australia are now up to 50% more airtight compared to those tested in 2015. This is a positive development for homeowners, as proper air tightness can contribute to improved comfort, reduced energy bills, and enhanced indoor air quality. By minimizing unintended air movements, air tightness helps to prevent outdoor air from seeping in and indoor air from escaping, leading to a more stable indoor environment.
On the other hand, poor air tightness can result in various issues such as drafts, increased energy consumption by up to 20%, and potential health hazards for residents. Buildings that are too airtight without adequate ventilation can lead to condensation, mold growth, and health problems like headaches and nausea due to higher levels of carbon dioxide and monoxide. The research conducted by CSIRO involved testing 233 recently built apartments and detached houses in major Australian cities, revealing both positive results and areas for improvement.
Senior Experimental Scientist and project lead, Michael Ambrose, explained that leakages were commonly found in new homes, particularly from sources like bathroom fans, sliding doors, and inadequate door seals. Additionally, some apartments were discovered to be excessively airtight, highlighting the need for controlled ventilation to maintain building performance and resident health. The use of a blower door test was instrumental in determining the leakage rate and pinpointing areas where air was escaping.
The research report put forward a set of recommendations aimed at addressing air tightness issues in Australian building codes. These recommendations include establishing air tightness standards in the National Construction Code (NCC), mandating controlled ventilation in new buildings, requiring the use of air barriers like building wraps in all new residences, and providing training for builders on cost-effective solutions to improve building performance. By implementing these measures, the study suggests that air tightness levels can be brought in line with the Nationwide House Energy Rating Scheme (NatHERS), which assesses the energy efficiency of residential buildings.
The alignment between actual air tightness levels and those predicted by NatHERS indicates the reliability of the rating system in estimating air tightness within acceptable limits. As a result, there is a proposal to include air tightness values on NatHERS certificates, allowing homeowners to understand the impact of air tightness on the energy efficiency of their homes. This transparency can empower residents to make informed decisions about improving the comfort and efficiency of their living spaces.
The research conducted by CSIRO sheds light on the critical role of air tightness in Australian homes and the potential benefits of addressing air tightness issues. By implementing the recommended measures and raising awareness about the significance of controlled ventilation and air barriers, homeowners can create healthier, more energy-efficient living environments. It is essential for policymakers, builders, and residents to work together to prioritize air tightness in building design and construction, ultimately enhancing the overall quality of residential buildings in Australia.