April 2, 2000
Window Shopping is a Pane
Following in tradition with other cordwood builders, last week I journeyed into the unknown searching for the ultimate deal on windows. The goal was to find some good quality windows that were mis-sized for one reason or another and to design the cordwood walls around the window, not visa versa. In doing so, these windows could be purchased at a fraction of the cost of custom made windows.
With this in mind, I decided to drive up to northern Wisconsin to visit some of the local window manufacturers. (This also gave me an opportunity to meet Rebecca and Richard Flatau. They have a beautiful cordwood home near Merrill, WI. Check out their web site, here at DayCreek.)
Over the course of two days, I visited three manufacturers and four "factory outlets". Maybe I just wasn't in the right spot at the right time or maybe I was just too picky. Whatever the reason, I came back empty handed. I did find windows that came close to matching my criteria, but not close enough. I wanted a window (casement, double-hung or slider) that was close to 4'w x 5'h. It also had to have low E glass, preferably 7/8" thermal break between the glazings. If I was more interested in cost savings than efficiency and consistency, I would have bought the windows, but I couldn't find 11 windows that matched in size and style. The 11 windows will be the windows that are used for the south and west facing sides of the house and esthetically, I wanted those 11 to match. But, I couldn't find 11 of the same kind.
So what did I end up doing? The answer was right under my nose. I didn't have to go to northern Wisconsin to find the windows. The answer was right here in our present home. About three years ago, we replaced all of our windows with a vinyl replacement window manufactured in Chicago. Chicago as it ends up, has a huge market for replacement windows. I called the manufacturer of the windows we have in our house and found out that they could adapt them to new construction. Their windows can be made to any size you like and cost only 20% more than a cheap, home improvement window. They have a full 7/8" thermal break and are low E. (Because I was buying more than 10 windows, the low E option was included for free!) The glass they use is double thickness and the vinyl casing is much more robust than the store bought kind. They turn orders around in a week and a half and they are made to any size that you would like.
If we presently lived in northern Wisconsin, I'm sure that over a period of 3 months or so, we could have collected enough windows (matching) for our house. But, since these manufacturers were over 250 miles from our present home, it made things a bit more difficult. If you plan on building a cordwood home and you've got some window manufacturers in your area, start looking as soon as possible. Be careful though, some of the prices on the windows that I saw were not that great of a deal. Shop around first.
Since we're on the subject of windows, here's my reasons for the type of window I was looking for:
Vinyl - It doesn't matter if a window is wood or vinyl, it's the glass that makes a difference when energy efficiency is the main concern. Wood windows are typically more expensive and require some maintenance. Vinyl windows offer the same energy efficiencies with no maintenance. The downside to vinyl is color selection. (White is the most common with some manufacturers offering a few other colors, but if color is important to you, a wood, aluminum clad window is probably the way to go.)
Low E - Low E stands for low Emissivity. There are a number of window attributes that will make a window more energy efficient. Low E is one of the more cost effective ways to increase the efficiency of the window without spending too much more on the window. Here's how it works:
Low E is a metallic substance that is applied to one of the inner glazings of an insulated (double pane window). During the winter, it reflects long-wave radiant heat back into the house (#3), while allowing a portion of the short-wave radiant heat through the glass (#1). In other words, the sun's (short-wave) infrared heat is passed into the house, while heat from your walls and floor (long-wave) is kept inside the house. During the summer, reflected heat (#2) off of the ground (long-wave) is blocked by the Low E glass. Just be sure to have a large overhang on the house or awnings for adequate summer shading. Also, be sure to check the specifications of the low E window first. Some low E windows are designed for warm climates while others are designed for cold climates. It's a matter of keeping the heat in the house or out of the house depending upon where you live.
There are plenty of ways to add other efficiencies to windows through triple panes, argon and krypton gas, and heat mirrors. Some windows boast values close to R-10 if you want to pay the price. Low E is quite inexpensive and basically adds the equivalent of a third pane of glass to a window.
High Solar Gain - For northern climates, make sure the window is rated with a high solar heat gain coefficient. A rating of .5 to .6 is a good number. The higher the better for northern climates. Windows that are tinted, will have a lower value. These are best suited for southern climates where keeping heat out of the house is a priority.
Double Pane 7/8" or greater thermal break - If you look at the quality of windows that are sold in most home improvement stores you will find windows that typically have double panes that claim to have 3/4" to 7/8" windows. After I viewed these windows, the only way they could be that thick is by including the entire thickness of the window, not just the thermal break. The larger the thermal break between the panes, the better R value you will get. If you can get a deal directly from a manufacturer, you can get a true 7/8" window for about the same price. Check around before you buy.
Slider or Double Hung - Originally I was looking for a casement window because they are the best style of window when it comes to stopping air infiltration. But, the newer sliders and double hung windows come close to the same specifications and there's no gears to strip or hinges to break. No maintenance wins again.
If you would like to learn more about energy efficient windows, take a look at: http://www.efficientwindows.org