If you’re considering purchasing composite windows for your new-build or replacement windows for your existing home, you might wonder about the benefits of choosing triple-glazed composite windows over normal double glazed products.
WHAT IS TRIPLE-GLAZING?
Essentially triple glazing is three panes of glass instead of one for single glazing or two for double glazing. Double glazing already offers a notable improvement in terms of energy efficiency and sound-proofing, so does adding a third pane really make that much of a difference?
Heat loss is normally measured by the thermal transmittance characteristics of a material or U-value. It is expressed in Watts/m²K and the lower the value, the greater its thermal insulation properties.
Single glazing, for example, has a U-value of little better than 5.0 W/m²K whereas typical double glazed products, depending on specification, can have a U-value of between 3.1and 1.6 W/m² which is why double glazing can reduce the amount of energy lost through a window by up to 75% and lower heating costs, typically by up to 20% each year.
With the unique construction of Westcoast Windows composite windows and doors we can achieve a whole window U-value of 1.4 for double-glazing and down to an impressive 0.8 W/m²K on some of our triple-glazed products.
These figures have been achieved through improvements in glass sealed unit performance and in design and manufacturing an aluminium and timber bonded construction to make a truly composite frame and sash.
The timber element acts as a natural thermal break enabling the frame to offer very high levels of insulation. This coupled with our high manufacturing standards in Sweden, creates one of the lowest U-value ratings on the market.
To put this in perspective current Building Regulations Approved Document L1A (Conservation of fuel and power in new dwellings) now stipulates a ‘Limiting fabric parameter’ for windows of 2.0 W/m²K in England (1.6 W/m²K in Wales & Scotland).
DOES TRIPLE GLAZING PAY?
In Scandinavian countries, where new buildings are highly insulated, triple glazing is mandatory due to the cold climate. Here in the UK where more temperate conditions prevail, definite consideration should be given to the small additional investment in triple glazed composite windows if your new build home is to be designed and constructed to high energy saving standards.
You might even consider triple glazing worthwhile for replacement projects as one of the key additional benefits when it comes to the comfort of your home is the elimination of cold spots around your windows which can cause draughts and potentially condensation issues.
So what we’re ideally trying to do is match the insulation value of your roof and walls which should be around 0.2 – 0.3 W/m²K. We still have work to do to achieve this, but essentially the lower the U-value of your window the more comfortable your home will be. Where double glazing makes a home more comfortable, triple glazing even more so.