Why Is Insulated (Double Glazed) Glass More Energy Efficient Than Ordinary Glass?

It’s undeniable. Windows in our homes afford us some of the most basic comforts inside our dwellings: warmth and light from the sun, and cool free air to breathe for proper ventilation. People living in a cold climate welcome solar heat and light most of the time. But for folks in warmer climates, it’s the light, not the heat they want.

Fortunately though, advances in window technology have made it possible to enjoy window functions both ways. Windows can be made more energy efficient. By installing energy-efficient window panes in your home, you can actually reduce energy costs by more than 30 percent. Various energy efficient glazing solutions are now available.

Multi-layered glass window panes or Insulated glazing units (IGUs) are energy efficient glazing units that can considerably reduce the amount of heat that may travel through your windows. One sure way of enhancing your home’s thermal comfort and save you money at the same time. Low-E (low emissivity) glass reflects heat energy while allowing visible light.  Heat is therefore kept out during the summer. And in the winter, low-angle visible light passes into the house and is absorbed by the home’s interior.

Ordinary glass windows on the other hand, readily transmit heat that is soaked up by the walls, furniture, floors, etc. in the summer. Unnecessarily, you use up to 60% more energy to cool your home. But if you utilize low E windows with low solar heat gain, you minimize the amount of heat entering your home, and actually need lesser amount of energy for cooling your home for warm weather months.

Another benefit is that, sunlight transmitted through the ordinary glass during daylight hours, is absorbed by the walls, furniture and flooring and many other valuable items as carpets, curtains, upholstery, artwork and wood which may fade and become devalued due to exposure to sunlight and ultraviolet (UV) rays. This is not so with energy efficient windows. In addition, during the cooler seasons, insulated products can create warmer interior glass surfaces, reducing formation of frost and condensation. In the long run, your new, energy-efficient windows eventually pay off well because of lower heating and cooling, even lighting costs. However, if your budget is tight, energy efficiency improvements to existing windows can also help.

Careful though.  Even the most energy-efficient window requires proper installation. Best to have a professional install your windows. Manufacturers recommend these window types to be properly air sealed during installation for superior performance.

More importantly, you can rely on Jim’s Glass to give you the right advice on glazing selection and installation. You have options that could get you the best result.


Jim’s Glass is proud to stock and glaze Viridian SmartGlass™, an energy-efficient range of glass that recently won the HIA Green Smart Award. You can also choose the additional benefits of Viridian ComfortPlus™ and Viridian ComfortHush™ to enhance the performance and amenity of your windows. These innovative products means you can effectively control the energy performance of your home using a superior Australian made, Australian guaranteed product.

Viridian SmartGlass™ and ComfortPlus™ are energy-efficient glass types that will insulate your windows and provide enhanced energy efficiency for your home. Smart Glass is a single panel glass with a ‘Low E’ coating, and can be used in many window applications and can also be toughened. ComfortHush™ is specially formulated three layer laminated glass, it has been designed to offer energy efficiency and sound reduction.

Viridian ComfortHush™ is the latest innovation in glass technology where the energy efficiency benefit of 39% better insulation of ordinary glass and a 6dB reduction (weighted average) over ordinary 3mm glass. A 6db reduction will give roughly the same benefit as doubling the distance between you and an unwanted noise source…noisy neighbours, traffic etc.


Jim’s Glass offers a complimentary in-home measure & quote service to discuss your ideas. During this time a trained glass specialist will discuss your options and provide you with a quote. Call 131 546 to book an appointment