No matter how beautiful the view from an old window, inefficient windows can contribute to a pretty terrible-looking energy bill year-round. Sure, maintaining a window’s weatherstripping can trim the losses, but the better long-run investment with older windows is replacement with models that incorporate the latest technologies for great style and energy efficient savings.
Replacement windows are definitely an investment, but one for which you’ll see immediate returns through the energy you’ll save in heating and cooling costs and a more comfortable environment indoors. What’s more, if you’re looking to sell your home anytime soon, the installation of energy efficient windows is attractive to potential home buyers and a move that can net a return on investment of around 80 percent, according to Remodeling magazine’s Cost vs. Value Report. Browse the following guidelines before you shop, and you’ll enjoy a beautiful view of cost savings on your energy efficient window project.
Replacement vs. new-construction windows
When shopping for energy efficient windows, it’s important to understand the structural differences between windows designed for new construction and those made to replace existing windows. New-construction windows incorporate a sort of fin along the outer frame, allowing them to be installed from the outside of a structure before siding is applied. Replacement windows, on the other hand, have no such fin or structural frame, and instead make use of existing window frames for installation from the inside of the home, with very little disruption to exterior or interior surfaces. If the existing frame exhibits damage, however, full-frame replacement windows are also available.
What you see on the label is what you get
As you shop for replacement windows, watch for the labeling that describes energy savings you’ll receive. Windows bearing the Energy Star seal are independently certified to perform at levels meeting or exceeding strict energy efficiency guidelines set by the U.S. Department of Energy. In addition to the Energy Star mark, pay attention to information provided on the National Fenestration Rating Council’s (NFRC) energy performance label, found on all windows and skylights.
The label includes the window’s U-factor, a measurement of how well it prevents heat from escaping; the Solar Heat Gain Coefficienct (SHGC), which tells you how well a product blocks heat caused by sunlight; the Visible Transmittance (VT), meaning how much light comes through the model; an Air Leakage (AL) rating equivalent to the cubic feet of air passing through a square foot of window area; and Condensation Resistance (CR), measuring the product’s ability to resist the formation of condensation on its interior surface. These critical numbers make it possible to comparison shop and select the best all-around fit for your efficient window replacement needs.
How many window panes do you need?
The choice between double- and triple-glazed windows comes down to the amount of draft, sound and UV protection needed for the environment in which you and your home reside. Low-emissivity (a.k.a. Low-E) glass is now common in both glazing formats, and has a thin layer of metal oxide coating that allows UV-filtered sunlight to pass through while keeping interior heat from escaping. Double-glazed windows incorporate this feature into a system with two layers of glass separated with a spacer and the insulation of air or a safe, colorless, odorless gas, working together to keep comfort indoors and weather’s impacts outdoors. Triple-glazed models add a third layer of glass along with impact resistance and sound insulation, but extra weight and expense are also part of the deal. Go with triple-glazed windows only if you live in the kind of extreme climate that makes these extras worthwhile.
Advances in glass
Savings, easy care and overall product efficiency is spurring innovations in energy efficient window design. For example, Andersen Windows and Doors has just introduced a SmartSun glass that helps reduce energy consumption in the home while providing year-round thermal protection and attractive visibility. Going beyond standard solar glazings that control heat gain through tinting, SmartSun glass is formulated with an additional microscopic layer of silver that controls the amount of infrared energy transmitted, allows a higher level of visible light, and blocks 95 percent of ultraviolet rays for protection of furniture, carpets and wall coverings. Besides being efficient, this solution also complements one developed for those of you who don’t do windows: Andersen’s High-Performance Low-E4 glass, which has an exterior coating that, when activated by sunlight, reduces water spots by up to 99 percent, promotes faster drying, and helps cut down on dirt buildup.
For more information on energy efficient windows, you can download Your Complete Replacement Window Guide, a free chapter from our book, My Home, My Money Pit: Your Guide to Every Home Improvement Adventure.