Window Basics – Part 1 (By Chad Vankoughnett)

It’s More Than Just Glass

New windows on an older home can be a great idea. Not only will they increase the value of the home, they provide better insulation, keeping your home warmer in the winter and cooler in the summer, and let’s face it…they look great. Replacing the windows on your home can be a big investment, not only in terms of money, but in time as well. With all the choices and styles out there, it can be pretty intimidating trying to select just the right windows for your home. I want to help make that easier for you. In this post, I want to help you understand the basic construction of residential windows. I won’t use a lot of technical jargon, but I will help define what some things mean and hopefully give you a small foundation as you begin researching this topic.
The first thing you need to know is that glass is a terrible insulator. Heat and cold move right through untreated glass, meaning that windows, especially in our climate, need to be designed and built specifically to counteract that problem. The insulation abilities of windows is measured with a different scale than the rest of your building envelope. Walls, floor, and roof insulation is measured as an R-value. You will commonly hear people talk about R-12 (the common insulation in a 2×4 wall), R-20, R-45, and the like. The more insulation, or rather, the more efficient insulation you have, the higher the R-value, and the easier it is to maintain a temperature inside the house. Windows are more commonly gauged by their U-factor. A U-factor of 0.30 is roughly equivalent to R-3.3, and is considered a pretty good insulation factor for double pane windows. The lower the U-factor, the better the insulating ability of the window, although unfortunately it also means a higher cost. A high efficiency triple pane window can reach a U-factor of 0.15, which equates roughly with an R-value of 6.7.

Windows are produced in single, double, triple, and even quadruple pane configurations. The configuration you choose for your home will depend on several factors, including cost, availability, cost, and probably cost. When we talk about multi-paned windows, we mean that there are that multiple sheets of glass separated by either a vacuum or a gas such as argon or krypton. In our area of the world, single pane windows are pretty rare (read “almost non-existent”) because of their very poor insulating ability, but double and triple pane windows are common. Double pane windows are usually filled with argon, an inert gas found in our atmosphere (you breath in about 2% argon all the time). Argon is much denser than air, and temperature has a hard time moving through this gas. Triple pane windows are almost exclusively filled with krypton, as it functions much better than argon in the smaller space between the glass panes. Krypton is around 3 times as dense as argon, making it even better at insulating your home. It doesn’t make a lot of sense to push for krypton filled double pane windows, though, as the cost savings for the extra insulation are more than offset by the extra cost for the gas.

Windows can also come with a special coating that reduces the heat transfer through the glass. This low-emissivity coating, commonly called Low-E, helps keep the heat out of your house in the summer, and the cold where it belongs in the winter. Low-E coatings are common, and a good investment in your windows, as it helps make your home much more comfortable in extreme temperatures, and reduces heating and cooling costs as well.

Windows are produced using several different materials for the frame, including wood, aluminum, vinyl, and PVC. These materials vary in cost and appearance, and there are some differences in the longevity and performance of various materials. Having said that, it really does come down to a matter of preference, as a well-constructed window will last a lifetime if properly cared for regardless of the materials used to build it. Talk to a professional about which windows will be right for your home.

In our next blog segment, we will take a look at common window configurations along with the various parts of a window, followed by a segment on taking proper measurements of your window in order to get an accurate quote. As always, if you have any questions or are interested in having a conversation about the windows in your home, be sure to call one of our window specialists here at J&H Builder’s Warehouse. Our expert advice, exceptional service, and professional installation team can make replacing your windows a breeze. One that you can see blowing through your yard, but never have to feel.

– Chad Vankoughnett