Australians are getting better at sealing their homes tight. According to recent CSIRO research, new Australian homes are now up to 50 per cent more airtight than those tested in 2015. This is good fiscal policy: tighter homes mean lower energy bills and reduced heating and cooling waste. But there is a catch.
Seal a house too well without proper ventilation, and you trap the air inside. That means whatever is in your home stays there: carbon dioxide from breathing, moisture from showers and cooking, volatile compounds from furniture and cleaning products. House burping is promoted as a low-cost method to improve indoor air quality, reduce humidity, and limit mold growth, and for Australians investing in energy-efficient homes, the practice is becoming more relevant than ever.
The practice itself is not new. The term house burping emerged as it spread virally on social media in January 2026, but Europeans have been doing it for centuries under the German name "lüften", which simply means airing out. In Germany, it is often legally mandated in rental agreements. What is new is that the current average new Australian home has an airtightness of 15.4 air changes per hour at 50 pascals, while a certified Passive House achieves a maximum air leakage of 0.6 ACH50. This dramatic tightening creates a genuine tension between energy efficiency and air quality.
Why sealed homes matter, and why they are risky
Poor air tightness can cause draughts, increasing energy bills by up to 20 per cent, while homes that are too airtight without controlled ventilation can lead to condensation, mould and health issues such as headaches and nausea from higher carbon dioxide and monoxide levels. Australia's newer building codes reflect this tricky balance. The National Construction Code 2022 sets minimum standards for design, construction, and performance of buildings in Australia, bringing together requirements for structural safety, energy efficiency, health, and amenity including mechanical and natural ventilation.
For homes that have been fully electrified and sealed, the challenge is acute. Draughts from old wall vents, chimneys and cooling ducts often remain from the era when homes were heated by gas or fitted with open fires. In Sandringham, Tim Forcey sealed his 1904 weatherboard cottage and discovered he needs to use a dehumidifier to manage moisture levels. He now opens his windows wide each morning for 15 minutes. By doing it before heating the home, he avoids wasting energy.
Two paths forward: manual or mechanical
Australians building sealed homes have two main options. The first is manual ventilation: opening windows strategically at times when outdoor air is cooler or cleaner than indoor air. House burping is more likely to be helpful when it is done in short bursts, away from busy traffic times, and on the sides of the home that face quieter streets or greener spaces. This costs nothing but requires discipline.
The second is mechanical ventilation with heat recovery. Passivhaus buildings are built on 5 building science principles: airtightness, thermal insulation, mechanical ventilation heat recovery, high-performance windows and thermal bridge minimisation. In Putney, Sydney, Susan Chan lives in a newly built Passivhaus-certified home where an energy recovery ventilation unit may be used in humid climates; energy recovery ventilation recovers both heat and humidity from the outgoing air, and in a humid climate where a dehumidifier is used, this enables the home to maintain lower humidity levels than outdoors.
Mechanical systems work but cost more upfront. Research shows that Passivhaus certification costs approximately 2-7 per cent more to build but reduces operational costs by 20-25 per cent. For households without the budget for such systems, manual ventilation remains an option, though it requires coordination and awareness.
The humidity problem
Australia's climate adds a complication. Coastal cities are consistently more humid than the healthy range. Increased carbon dioxide levels inside buildings can have negative health effects; 350-1000 ppm is the typical level found in occupied spaces with good air exchange. But humidity is a separate problem. Opening windows in humid summer air in Sydney or Brisbane can worsen the problem rather than solve it. Summer ventilation works best at night or early morning when temperatures and humidity drop.
This is where control matters. A person who can deliberately manage when and where they open windows beats a leaky house that bleeds air all day. Manual or mechanical, the principle is the same: ownership. Replace uncontrolled air leakage with intentional, managed ventilation.
For Australian homes undergoing electrification and energy sealing, window burping should be part of the plan. It is not a replacement for proper building science or mechanical systems where budgets allow. But for a cost-conscious household in an efficient home, brief, strategic window opening offers real benefits to health and air quality without undoing the energy savings that made sealing the home worthwhile in the first place.