Double glazing – without the hefty price tag

Note from Michael: this article was kindly contributed by Libe Chacos, author of The Better Building Guide – Thanks Libe!

There are around 8 million homes in Australia and many millions more around the world that have been built without real consideration of energy efficiency, the comfort of those who live in them, rising power costs or the impact on the environment.

If you live in one of them, you can easily transform your home and:

  • Dramatically reduce your heating and cooling needs
  • Slash your energy bills and greenhouse gas emissions
  • Make your home much more comfortable all year round

Industry reports have shown that even when a house is fully insulated – walls, floor and ceiling, that up to 48% of the heat loss occurs through single glazed windows.

The following are qualities that will help you to choose the most appropriate glass for your situation:

  • The U-value or R-value
  • The Insulation level of the window (not just the glass); the lower the better
  • SHGC – Solar Heat Gain Co-efficient.  This is expressed as a number between 0 and 1. The lower a window’s SHGC, the less solar heat it transmits.

So let’s take a look at one alternative and see how it applies the right principles of energy efficient windows to save you thousands of dollars on your heating and cooling while you do your bit for a much better environment:

Double Glaze your home for under $400

Double glazing usually consists of two layers of glass and therefore costs an arm and a leg. But there’s alternatives you can install yourself such as a transparent membrane you attach to the inside of your window frame to provide a still air gap and thereby create a double glazing effect.

Depending on the type of windows you have in your home some supplementary framing or support may be required. I have installed the ClearComfort membrane on a house in Canberra (Australia) which is well known for being terribly cold in winter and very hot during summer. The effect was instant and surprisingly good. Condensation was pretty much reduced to zero and you could really feel the difference when touching the membrane to how cold the glass used to feel.

To avoid condensation occurring in the air gap you should the membrane system when the air humidity is low. You should also check that there is no moisture trapped between the glass and the frame and also that the frames are in good order and won’t let moisture into the air gap from the outside. If you have recently been renovating or painting, ensure that any paintwork or silicon etc has thoroughly cured.

Membrane installation

The membrane is fixed in place using double sided tape, cut to size and then made taut using a hair drier. There is a little patience and skill requited to do a good job. It’s recommended to use two strips of tape placed side by side for large windows, thus effectively doubling the tape width, eliminating any problem using these products on large windows. So even with large windows, in many situations the system is unobtrusive and an excellent addition to making your home more comfortable.

The ClearComfort system is available internationally and has been tested by a NATA accredited auditor using the Australian Window Energy Rating Scheme (WERS) developed by the CSIRO and the Australian Window Association. ClearComfort and other similar products are eminently suited to affordable sustainable housing, in particular to retro-fitting, while providing the same insulating U-value as plain clear double glazing.

Other alternatives

Have a look at some alternatives and find which is available in your area. You can use different solutions in different rooms of your home; for example films can be applied to provide shade during the hotter months. North facing windows may need to be treated differently to south or west facing windows.

Remember use the fundamentals to your advantage and always ask suppliers or sales consultants how their product performs or improves the following areas:

  • The U-Value of the window
  • The SHGC
  • Maintenance / warranty

It is easier than most people think to have an energy efficient house. You can make a dramatic improvement to your heating and cooling bills with a small investment and lessening your environmental footprint as you do so.

Libe Chacos from Sunrise Homes offers easy to follow advice and recommendations on how to create a sustainable and energy efficient home that feels great to live in. They follow the first forgotten principle of sustainability – sustain your budget! Find out more about The Better Building Guide