The window industry, as with every other industry, is being reshaped by technological advances and a growing concern for the environment. We are all looking at how we can help reduce our carbon footprint, protect our homes from harsh weather and other dangers, all while saving a few bucks. This has made window shopping more than simply choosing between frosted or clear glass to fit the frame.
Energy efficient windows are easy to identify because of three rating systems that are used to evaluate windows:
- Emissivity (low-E). This refers to the amount of infrared and ultraviolet light that is able to pass through your glass. Uncoated glass typically has a thermal emissivity of 0.91. This can be reduced by coating glass in a clear metal which would minimize the amount of ultraviolet and infrared light that can pass through glass without compromising the amount of visible light that passes through. One company even claims their low-E glass has an emissivity of 0.02.
- R-values. This rating indicates the energy efficiency of building materials in insulation and windows. The higher the rating more resistant the material is. Single pane windows, for instance, have an R-value of 1, while double-pane windows can have R-values as high 4.0. Triple-pane windows can go as high as 5 to 7 in the R-value range. These values can be augmented by combining double- or triple-pane windows with low-E glass for better results!
- U-factor. This value is determined by measuring the heat gain or loss through windows, doors and skylights conduct non-solar heat by comparing the difference in air temperature outdoors and indoors. The lower the U-value the more energy-efficient the windows are. Don’t confuse this with R-values where the higher values mean more energy efficiency!
From here on, your window choice should be determined by two connected factors: safety and design. When designing a new home, you will have to carefully calculate where you will place your windows. They not only have to be strategically placed so your rooms receive sufficient light, but they also need to be placed so that children can’t open them from inside.
After protecting them from the inside, you have to consider how the windows appear from the outside. This isn’t only for design reasons, but also to protect them from burglars. You could consider bulletproof glass or burglar bars, but even choosing an aluminum frame over a wood frame could be safer.