Double glazed windows are one of the great innovations in building sustainability and security. Widely attributed as an invention of Victorian-era Scotland, double glazing (plus triple, and now even quadruple glazing) is characterised by multiple glass panes with a hermetically sealed layer of air or gas.

Most people know double glazing has benefits for energy efficiency, security, noise reduction and heat transfer. But how is double glazing made, and what separates high quality double glazed windows from cheap-and-nasty alternatives?

How double glazing is made

Double glazed windows have three layers sealed together in a single unit: an external glass pane, air gap, and internal glass pane.

Joins are closed with sealant and the window clad in a weather-resistant airtight uPVC frame. Energy – heat and sound – cannot pass through these layers as efficiently as single pane windows.

External pane

The first line of defence against UV rays, heat, cold air, rain, wind and noise. We use a special Low-E (low emissivity) coating on the inside of the external pane to limit UV exposure by 75% and reflect warmth, keeping your home at a comfortable temperature all year.

Air gap

The unique element to double glazed windows. Air or argon gas is trapped between the two glass panes to create an insulating layer with the additional benefit of acting as a sound barrier. We use an air layer to offer affordable, high performing double glazed windows that outperform Australian standards. We also pack the base of the frame with a moisture-absorbing desiccant to prevent condensation.

Internal pane

Finally, a clear internal pane completes the hermetic air seal and provides unobstructed views. This pane, combined with the air gap, helps trap air inside the house to reduce reliance on heating and cooling appliances.

Double glazed windows only offer the full range of benefits when they are made to measure and installed millimetre-perfect to create a full seal.

What to look for in double glazed windows

Glass type

• Low-E coating makes glass more energy efficient and reflects up to 75% of the sun’s UV rays
• Toughened glass is treated to be 5 times stronger than regular glass
• Laminated glass is even tougher, earning a Grade A Safety Glass rating
• Toned glass uses an additive during manufacturing to obscure the glass for privacy

Gap size

• An air gap between 12mm and 20mm offers effective insulation
• Air can be replaced with argon, xenon, or krypton (although this normally increases cost)
• Some budget suppliers use 6mm to 12mm gaps which are not thermally efficient

Frame material

• The most common window frames are aluminium, uPVC and timber
• Even treated timber can warp or crack in extreme weather or coastal conditions
• Aluminium is less energy efficient than uPVC because it has high conductivity
• uPVC (un-plasticised Polyvinyl Chloride) is the best choice for insulation, lightness, and aesthetics

Locking mechanism

• Windows are a common target for home invaders
• Avoid single-point locks as these are easy to break
• Multi-point locking systems create an effective barrier against intruders

ARCO Double Glazing manufacture and install double glazed windows and doors to keep Perth homes and businesses secure, reduce energy bills, and increase year-round comfort. We use the highest quality European glass with energy-efficient Low-E coating as standard, and can custom make the windows to suit your preference.

Get an instant estimate on double glazed windows through our website today and enjoy the benefits for less than you might think.