7 Star Energy Rated Windows: What They Are and Why They Matter for Your Home
7 star energy rated windows are becoming a standard requirement for new residential builds across Australia following changes to the National Construction Code, and an increasingly common upgrade choice for existing homeowners who want their home to perform at a modern standard. Understanding what a 7 star energy rating means for windows, how it is measured, and what products achieve it helps you make a better decision when upgrading or building. This guide covers the key points.
What the 7 Star Energy Rating Means
The 7 star energy rating refers to the Nationwide House Energy Rating Scheme, known as NatHERS. This scheme assesses the thermal performance of a home on a scale from zero to ten stars, with higher ratings indicating better energy efficiency and lower running costs for heating and cooling.
The 2022 National Construction Code raised the minimum NatHERS rating for new residential buildings to 7 stars, up from the previous 6 star requirement. This change reflects a national commitment to reducing residential energy consumption and improving the comfort and resilience of Australian homes.
Windows play a significant role in a home’s NatHERS rating. They account for a large proportion of heat loss in winter and heat gain in summer, which means the window specification directly affects whether a home achieves its target rating.
How Windows Contribute to a 7 Star Rating
Achieving a 7 star NatHERS rating requires attention to the whole building envelope, but windows are one of the highest-impact elements. Here is how 7 star energy rated windows contribute to the overall rating:
- Low U-value: The U-value measures how much heat passes through the window from inside to outside. A lower U-value means better insulation. Double and triple glazed uPVC windows achieve significantly lower U-values than single-glazed or aluminium-framed alternatives.
- Solar heat gain control: The solar heat gain coefficient measures how much solar radiation passes through the glass into the home. Selecting the right glass specification helps balance winter solar gain with summer heat rejection.
- Airtightness: Air infiltration through poorly sealed windows is a significant energy loss pathway. Multi-point locking systems that compress seals evenly around the frame are essential for achieving low infiltration rates.
- Frame conductivity: uPVC frames have a much lower thermal conductivity than aluminium, which contributes meaningfully to the overall U-value of the window system.
What Astellite Offers for 7 Star Rated Homes
Astellite manufactures and installs 7 star energy rated windows across homes in Melbourne using German-engineered Aluplast uPVC profiles and high-performance Lightbridge double glazing. The products are WERS-rated, which provides the independently verified performance data needed to support NatHERS assessments. Triple glazing is also available for applications where maximum thermal performance is required.
The range includes tilt and turn windows, awning windows, sliding windows, bifold windows, fixed windows, bay windows, corner windows, and custom windows. Every window is custom made to your home’s exact dimensions and installed by Astellite’s own team.
Astellite holds accreditation from both AGWA and WERS, and all products meet Australian building and safety standards including bushfire compliance where applicable. Every installation is backed by a 10-year warranty.
Get a Free Quote Today
Astellite services homes in Melbourne, Geelong, Melton, and the Mornington Peninsula with free, no-obligation quotes. Contact us today to arrange your measure and find out how 7 star energy rated windows can improve your home’s performance.