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Understanding U Values: Why it's More Important Now Than Ever


With energy efficiency compliance becoming more and more important within the Australian construction landscape - it is critical to understand ratings around energy efficiency levels.

If not for your home comfort, then for the sake of overall energy efficiency and minimising heating and cooling costs. When it comes to windows and doors, if there is one efficiency value to have a good understanding of, it is the U value (often expressed as Uw).

What is a U Value?

In essence, a U-value measures how well a product insulates, by measuring how well a product is resistant to heat flow, and the easier it is to regulate the building’s heat internally. A lower U-value indicates higher insulative performance and greater energy efficiency.

U-value ratings in Australia typically fall between 2.0 and 10.0. (With 2.0 typically at the higher-performing end).

U-values aren’t based on a single material, but rather a combination of various components and calculations - considering the entire window assembly including the frame, the glass, seals and any spacers.

Why Understanding U Values is Important.

U values are a crucial part of how NatHERS (the Nationwide House Energy Rating Scheme) calculates their star ratings. The National Construction Code is likely to mandate a shift from a 6-star energy efficiency minimum to a 7-star minimum from the 1st of October 2023 - so understanding the energy efficiency of your windows and doors is critical towards maintaining compliance.

Any energy compliance reports specifying U ratings will have to feature a value either equal to or lower than that specified.

How Do I Check The U Values of My Windows?

All Southern Star Group U-values (including Canterbury Timber Windows & Doors and Southern Star Aluminium Windows and Doors) can be viewed on the Window Energy Rating Scheme (WERS) website.


If unsure about energy requirements for your windows and doors, get in touch with our team.


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