If you’re thinking about replacing your windows, you’ve probably gathered that double pane windows are a better investment than single pane. With only one pane of glass, single pane windows offer no insulation against outside temperatures. Double pane windows, on the other hand, provide a layer of insulation that can keep out unwanted cold or heat; they will keep you comfortable while saving you a substantial amount of energy and money.
If two panes and better than one, perhaps you’re thinking that three window panes are better than two. And you would be right – to a point; triple pane windows do offer better performance than double pane. But is that enough to make triple pane windows the right choice for you and your home? Here the answer isn’t quite so clear-cut. Let’s compare some costs and benefits:
Generally speaking, a triple pane window should be 20-30% more energy-efficient than a double pane window. That’s a substantial difference – but probably not one that’s going to greatly affect your energy bill; a difference like this is liable to yield an energy cost savings of around 2-3%.
As mentioned above, the difference between single and double pane windows is more compelling. Replacing single pane with double pane ENERGY STAR-certified windows would be expected to yield an energy bill savings of around 20-30%. If you live in an area prone to cold winters or hot summers (or both), your savings could be even greater.
Do keep in mind that windows vary in more ways than the number of panes. Window treatments and coatings play an important role in efficiency as well. Renewal by Andersen replacement windows, for example, features a coating called SmartSun; thanks to SmartSun, these dual pane windows are even more efficient than most triple pane windows.
Generally speaking, triple pane windows can cost a third more than double pane windows. Where a double pane window replacement costs $6000, a triple pane window replacement could cost $8000. If you’re saving $600 per year by upgrading from single to double pane windows, you’ll make back your investment in just 10 years; if you’re upgrading from single to triple pane windows, you should make back your investment in about 14 years.
A comparison between double and triple pane windows tells a different story. As indicated above, triple pane windows can cost thousands more than double panes. But the cost savings they yield will be only 2-3% of your energy bill; saving at this modest rate means it will take a long time to pay for the upgrade from double to triple panes.
Money isn’t the only consideration when it comes to windows; comfort is another. Imagine a snowy winter’s day. Old windows with poor insulation will be cold to the touch; this cold can create air currents – the drafts that can make us uncomfortable in winter. But windows with more insulation will not be as cold, and will not be as likely to create unwelcome drafts. Triple pane windows offer superior insulation, and will be able to keep you cozier and more comfortable.
If you’re trying to isolate yourself from exterior noise, replacing your windows can make a big difference. Relative to single pane windows, double and triple panes offer much better sound insulation. But again, there’s a much greater difference between single and double pane than between double and triple pane; if noise reduction is your goal, you’ll get little benefit upgrading from a double to a triple pane.
The Bottom Line
Replacing old single pane windows with energy-efficient double or triple pane windows will reduce your energy bills while increasing your comfort. Double pane windows can almost match the benefits provided by triple panes – but for substantially loss cost. Unless you are willing to pay additional thousands of dollars for even a modest benefit in efficiency and comfort, double pane windows are the smart choice.