What are double glazed windows?

Double glazed windows and doors—sometimes called Insulated Glass Units, or IGUs—use two separate pieces of glass which are separated by a central air gap, usually filled with Argon gas. Argon is an inert gas (meaning it has extremely low reactivity with other substances) that can dramatically assist with insulation.

Basically, the Argon layer helps to ‘trap’ any warm or cold air produced by heating or air conditioning systems, which can help to keep you cooler in summer and warmer in winter.

What are the benefits of double glazed windows?

Huge energy bills are a burden most families can do without; higher energy efficiency performance can maximise energy usage to reduce heating and cooling costs over time.

Windows play a vital role in the overall energy efficiency of a family home, with the average household losing up to 40% of its heating and cooling through its windows*. Double glazed windows and doors are a highly effective option for maximum energy efficiency.

Thanks to the energy efficiency of double-glazed windows, there are two main benefits:

1. You can save on power bills.

Double glazed windows are incredibly effective at ‘trapping’ the hot or cold air that is produced by heating or air conditioning systems. The improved insulation of double glazed windows means this air is less likely to leak out of the house, which in turn means your home can retain a pleasant temperature for longer. As a result, you can run your heating or cooling systems less frequently. Less time spent running your systems typically means less outlay on energy bills.

2. You can consume less energy, which may be better for the environment long term.

The less power usage throughout the community—due to more effective insulation in homes—the less need for power generation, which can be better for the environment long term. This is one of the many reasons that sustainable and energy-efficient home design are becoming increasingly key considerations for state and federal governments.

How effective are double glazed windows?


In cooler climates, like Victoria or Tasmania:

  • Double glazed windows can prevent up to 55% of heat loss.
  • Double glazed windows with low e glass can prevent up to 70% of heat loss.


In warmer climates, like Northern Queensland:

  • Double glazed windows with low e glass can prevent up to 77% of solar heat gain, keeping you cooler for longer.

Sources: Australian Glass and Window Association (AGWA – previously AGGA) Window Energy Rating Scheme (WERS) visit: www.wers.net/wers-home

* The performance figures shown are based on heat gain through glass only. Data has been calculated using NFRC 100 – 2001 environmental conditions and Window 5.2 software from the Lawrence Berkeley National Laboratory (2006). Savings are in comparison to using 3 mm clear glass and may vary depending on actual operating conditions. Source AGWA.

Which products are available with double glazing?

All A&L products are available in a double glazed configuration. Get in touch with the team today for more information on the best option for you.

Contact the team

Speak to your A&L sales representative for more info about design options for your next project.