Thousands of newly built Aussie homes already 'unsafe'

As urban sprawl marches outward from Australia's biggest city, outdated building codes are creating a serious problem.

Tens of thousands of brand new houses in one of Australia’s fastest growing regions will be outdated and potentially unsafe by the time they’ve finished construction.

And the worst part? It’s completely 100 per cent legal.

Because of outdated building codes, new houses in western Sydney —which four years ago was the hottest place on earth at nearly 50 degrees — are actually being designed to retain heat, rather than stay cool. This is alarming. And it isn’t just a small stretch of houses either.

Left - an aerial view of a housing estate in Western Sydney. Right - Samuel Austin in Western Sydney.
Samuel Austin (right) is warning many new homes in Western Sydney could be unsafe. Source: SIX Maps/Supplied

In just the past five years, over 36,000 new homes have been built using these outdated building codes in Sydney’s urban release areas. And based on current forecasts, another 35,000 new homes will be built in the next five years using these same codes.

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How hot are these new houses getting?

A joint report led by WSROC – a coalition of councils in Western Sydney – investigated the issue. Their study tested a typical brand new single-storey house against a historic heatwave in 2017. It found that even with the air conditioner running, the daytime indoor temperature crossed 28.5 degrees — well above the maximum range for a safe working environment.

And what about during a blackout when residents can’t run their air conditioner, a common and regular occurrence during days of extreme heat in western Sydney? Indoor temperatures reached a maximum of 37.6 degrees, and exceeding 30 degrees for seven hours.

Houses being constructed in Western Sydney with an inset of the WSROC report - Future Proofing Residential Development in Western Sydney.
Western Sydney councils issued a report about future-proofing developments in Western Sydney. Source: WSROC/Supplied

Why are we using outdated building codes?

New houses in NSW must be built to a standard considered "thermally comfortable" due to a law called ‘BASIX’ – which essentially means a house can’t get too hot or cold to endanger human life. This is a positive thing.

But there is something very backwards about this law. It is effectively ignoring climate change.

Currently the law requires houses to be built to be "thermally comfortable" in the historic climate of 1990 to 2015. And this is causing some big problems. Historically western Sydney had a longer “cool period” than it did a “hot period”. But that is no longer the case.

When modelled on current climate data and forecasts for the years 2010 – 2029, WSROC found a new house was already unable to meet the minimum standards to be "thermally comfortable".

And when modelled against the forecasted 2050 climate? The study found that these new houses could be risking human lives.

How the building code problem gets even worse

The "thermal comfort" test assesses a new house with an air conditioner on. This is a massive problem to assume that all homeowners can run their appliance all day in the middle of a cost of living crisis, let alone when a blackout hits.

It’s important to note that these BASIX laws have always assessed homes against historic data. But when introduced in 2004, climate change was not as well understood as it is now, 20 years later.

More planning stories by Samuel Austin

Left - Typical black-roofed houses in western Sydney. Right - an aerial view of houses in Winton where some of the roofs are white, and others are dark grey.
While black roofs (left) remain popular in western Sydney, switching to lighter colours (right) can reduce heat around the home. Source: Supplied/SIX Maps

What can we do about the housing code problem?

Fortunately for new homeowners, WSROC has identified a number of lower cost ways to address this issue for existing homes.

Installing ceiling fans to living rooms and bedrooms can greatly improve internal thermal comfort. Adding external shading devices to windows can avoid heat gain. And importantly, changing external walls and roofs to lighter colours will have a significant reduction in heat generation.

It’s not impossible to address this issue. We have both the expertise and knowledge to solve it, we just need to make sure it gets implemented.

Samuel Austin was the NSW Young Planner of the Year in 2022. He is a TEDx Speaker and a social media influencer on planning issues.

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