If you’re considering window options for your new home, you might be wondering what you need for the best thermal insulation. Is a modern single-glazed window enough, or do I need double to create a proper ‘thermal blanket’ effect? Is triple-glazed a good option, or is that simply overkill for a new home?
Here, we’ll discuss the merits and points to consider in all three options.
Glazing is the glass component within your window frame. How well this glass is sealed within your frame, the type of material, fixture and glass thickness all contribute to how well insulated the window will be.
However, if you’re concerned about a particular material letting in more cold air, you shouldn’t be. At Koffman’s, we offer both uPVC and aluminium window framing, which is heavily insulated inside the frame, minimising the heat loss.
Although it depends greatly on the frame insulation and the quality of glass you use, single-glazing won’t offer the thermal insulation blanket you get with double or triple-glazing. This is why the new H1 standard essentially excludes the use of single-glazed windows in New Zealand homes.
Double and triple-glazed windows are naturally better insulators. Unlike single-glazed windows, they contain air or gas between the panes of glass that act as a thermal barrier and so naturally have a lower U-value (the measure of thermal transmittance). This means less heat escapes home, which increases the ability of your heat source to effectively cover a house or room, lowering your overall energy bill.
Similarly, double-glazed windows prevent external heat from entering the home in the summer, which results in a more comfortable room temperature throughout the year.
The things to note with double-glazing are the amount of space between the window panes and the size of the individual panes themselves. Greater space allows for more of an insulating blanket while having one thinner pane (around 4mm), and a thicker pane (around 6mm) can more effectively cancel out noise.
Triple-glazing works twice as well as double-glazing when it comes to thermal insulation and energy efficiency. Whereas double-glazing typically has a U-value of 1.5-3.5, triple-glazing can get down to 0.5, which means minimal heat seepage. The effective resistance means less condensation on the glass so that you can preserve a better quality view throughout the year without moisture buildup.
Triple-glazed windows are also much more secure and challenging to break through compared to single or double-glazed options.
The best glazing solution depends on what you’re trying to achieve with your windows and the surrounding area you live in. For New Zealand, particularly in the colder Southern regions, an extra thermal barrier in your window frames may be needed during winter. If you view your home build as a long-term investment (anywhere over ten years), triple-glazing may also be the way to go, as the investment pays itself off eventually in energy saved.
The number of window options doesn’t stop with the number of glass panes you use.
The type of gas which serves as a filler between panes also contributes to the effectiveness of your insulation. While some windows use krypton, air or a simple vacuum, at Koffman’s, we use argon gas, a high-performing insulator suitable for virtually any climate. With the proper window frame, gas leakage and condensation can be managed over time, greatly increasing the lifespan of your window.
Another small improvement can be the use of warm plastic spacers joining the glass pane instead of the typical aluminium option. The size of the gap between the glass is important too. Best windows offer 18mm space in the triple-glazed version and 24mm in double-glazed windows. All our frames at Koffman are enabled to support these superior insulated glass units.
For more information on choosing the right window for your New Zealand location, see our other article on changing H1 standards.
At Koffman, we import premium window and door solutions from Europe, answering to the highest standards overseas and using the latest techniques. Our windows can be customised to reflect your ideal colour palette or shape and come in two different framing styles; uPVC and insulated aluminium.
If you’d like to know more about the window solutions we offer or get a quote based on double or triple-glazed windows, contact us. We can give you a free quote based on your home-building project and talk you through various options, depending on where you live in the country.