Newly released analysis suggests that by upgrading Australia’s worst-performing homes, the energy savings would be equivalent to keeping 4.5 million electric vehicles on the road a year.
Residential buildings are responsible for around 24% of overall electricity use and more than 10% of total carbon emissions in Australia according to the Department of Climate Change, Energy, the Environment and Water (DCCEEW to its friends).
While standards relating to energy efficiency for Australian homes have certainly improved over the years, millions of houses were constructed prior to any minimum standards existing. Currently, the minimum energy standard for new builds is 7 stars under the Nationwide House Energy Rating Scheme (NatHERS).
But homes built before 2003 generally have a pretty poor rating; making them heating and cooling money pits, and just plain uncomfortable. I remember our house in Canberra, built around 1973, having a metal roof and no insulation to speak of. Summers weren’t much fun (no air-con) and in winter we used an oil heater in the lounge and electricity-guzzling fan heaters in the bedrooms.
Climateworks Centre operates as an independent not-for-profit within Monash University, working to bridge the gap between research and climate action not just in Australia, but elsewhere in the Pacific region and South-East Asia. The organisation recently built on its “Enabling Australia’s Home Renovation Wave” report released in 2023.
For the purposes of their new analysis, Climateworks defined low-performing homes as having:
- Minimal ceiling insulation.
- Gaps near windows and in walls leaking air.
- Gas heating.
The Centre considered these low-performing detached homes and townhouses to have a NatHERS rating of between 2.3 and 2.9 stars, while apartments were between 2.7 and 4.2 stars1. It conservatively estimates at least 10 per cent of total dwellings – more than 1 million homes in Australia – to be in this category.
Energy Efficiency Packages For Places
The Centre developed several upgrade thermal upgrade “packages” for this exercise, being:
Quick-fix
Ceiling insulation, draught sealing, heavy drapes and roller shutters along with an efficient electric heat pump (assumed to mean reverse-cycle air-conditioner rather than a heat pump hot water system). This would provide a NatHERS rating of between 3.4 and 5.1 stars. Estimate cost per residence: $13,700.
Modest
The above plus floor insulation and an additional layer of glass or film on windows; bring properties up to between 3.6 and 5.4 stars. Estimated cost of $19,000 per dwelling.
Climate-ready
Quick-fix plus floor and wall insulation, high levels of draught sealing, double-glazed windows and a heat recovery ventilation system, which brings the rating to between 6.3 and 8.7 stars. Estimated cost of $37,100 per home.
As for the package recommended for each state/territory:
- NSW: Modest
- VIC: Climate-ready
- ACT: Climate-ready
- QLD: Quick-fix
- SA: Climate-ready
- NT: Quick-fix
- WA: Modest
- TAS: Climate-ready
Quick Fix – Cost Vs. Value
That “Climate Ready” package is really pricey – what if the “Quick-Fix” package was used throughout instead? For the 1,069,509 homes nationally, that works out to around $14.65 *billion*. Still ouch, just not yelled quite as loud. That would buy a lot of rooftop solar and home batteries; although that wouldn’t address the root issues.
But what would be the benefits of quick-fix?
According to Climateworks, the approach would result in:
- A 1,471.9MW reduction in total peak demand.
- Annual energy consumption savings of 8,418.2 GWh.
- Annual emissions savings of 2,204,558 tonnes of carbon dioxide equivalent.
- A collective $1.81 billion in annual energy bill savings.
That would put simple payback for the whole shebang at around 8 years.
One of the aspects I found confusing was the energy bill and emissions savings “includes electrification of cooktops and hot water in addition to thermal upgrades where indicated”. But it doesn’t explain if their inclusion affects the average upgrade costs as neither was mentioned in the packages. And I’m guessing “where indicated” means “where needed”, rather than certain states/ territories as there were no flags for this on any jurisdictions.
While acknowledging there are some programs already in place around Australia supporting various energy efficiency upgrades (such as Victoria’s VEU program), Climateworks says more government action is needed.
Footnotes
- According to CSIRO, homes built before 2003 typically average a NatHERS rating of around 1.8 stars. ↩
About Michael Bloch
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It’s all very well to promote this, but how many companies are competent of doing such?
A relative building a few years back wanted particular insulation in the walls – I forget the R rating. When it came time to actually build, oh sorry but the framework doesn’t permit that rating, we’ve had to downgrade to a much lower rating to fit the insulation in.
When phoning around to see if regular glass, double glazing, e-glass, or whatever was the best option, the building company had zero expertise, the glass seller couldn’t help, and the glass company said it was all basically the same no real difference. So why bother going double-glazed if the ‘experts’ say there’s no difference?
To be clear, I’m not critiquing the recommendations in the SQ piece, only that competency, or expertise, is rare.
Hi George,
You’re dead right.
Australians build sh!t houses and it starts with builders & designers who care more about what shade of insipid grey is fashionable than something as fundamental as where is North?
“Tradies” generally slap things together badly, as speed is king and training is poor.
And the enforcement of what are pretty poor energy standards is non-existent. The house plan that says 6 star “as designed” never gets inspected and tested to standard.
As proof, builders in SA have been given a special carveout so they don’t have to comply with new energy standards for another ten years.
Utter short-sighted stupidity because the building industry has corrupted the planning process.
They really jumped to the expensive options for all scenarios.
Here’s an alternative for mult-storey strata buidlings:
All levels except for the top floor already have excellent floor and ceiling insulation. Only the top level benefits from roof insulation.
Cheap resistance HWS can use a timer or smart switch to run or cheap or free solar electricity in the daytime.
Who wants heavy drapes today. There are plenty of reasonably priced blind options around without using shutters, although some people like plantation shutters.
Replacing worn window seals can reduce air leaks.
Publish useful hints for (older) unit dwellers to understand how to manage air-flow to control moisture and temperatures.
These changes are reasonably inexpensive with rapid paybacks and can make a significant change to costs and comfort
They don’t need to be hard, high-tech or expensive.
1. Where did you find 1 billion.
2 since ventilation has beaten stopped in husess thee population has been getting ill more.
3 more mold in ouses carousing people more illness
Hi Ian,
People are pretty helpful in these comment threads, so I don’t mean to be disparaging but you’ll have to improve the quality of your questions to get credible answers.
Please rephrase and maybe cite some sources about ventilation?
Cheers