Friday, July 14, 2006
Tips on window frames and glass
By Ann Robinson and Annie Vernon
Last week we started a two-part look at windows. Windows are an important part of your remodel. You may be adding windows to capitalize on natural light or a particular view. You may be replacing old, inefficient windows to save energy costs. Or you may be looking to change the style or functionality of your windows.
Whatever your goals, you need to be particular about the windows you choose.
Last week we talked about common styles. This week we will look at more technical aspects: the material of the window frame and various options for glass.
Once you have selected the best window style for your home, the next decision is the material from which the frame is made. Aluminum frames are inexpensive and lightweight and come in various finishes and colors from the factory. They are essentially maintenance free, but they cause conductive heat loss and therefore can be an inefficient choice.
Vinyl windows are strong and provide good energy savings. You can select various colors, but dark colors can run into problems of warping and fading in the heat. Vinyl also does not receive paint well. Vinyl might also not be the ideal choice of material for restoring an old home since vinyl wasn't a material used in the early 20th century.
Wood windows are less affected by temperature extremes and have fewer condensation problems. They are a great choice for restoring an early 20th century home. However, wood frames can be expensive and require considerable maintenance with regular painting. You can get wood windows which have the exterior wrapped in aluminum or vinyl to reduce exterior maintenance issues.
Fiberglass is a more recent option for window frames. This is a very stable material which allows the use of darker colors such as brown and forest green. It is excellent in terms of insulation and is more expensive than vinyl.
With the framing material chosen, you need to decide which type of glass or "glazing" to use. As windows evolved throughout history, they have been covered with anything from hide to thinly sliced marble. By the 20th century, glass became common. Today glazing has advanced to include multiple "layered" panes and energy efficient technologies.
Most new windows are sold as double paned units, sometimes called insulated glass. The space between the two pieces of glass can be filled with a gas which is a poor thermal conductor, thus reducing the heat that passes through.
Glazing can also come with coatings and tinting. Low-emissivity (low-E) is the most common coating in residential windows. This is an invisible layer of metallic oxide that reduces the amount of heat that passes through the glass. Low-E coatings add up to 20 percent to the cost of a window, but they also cut energy expenditures by about 25 percent. Low-E coatings also filter ultraviolet rays which helps protect furniture, carpets, and artwork.
Finally, one good way to get energy-efficient windows is to look for Energy Star windows. They come with multiple panes of glass, gas fill, low-E coatings, warm edge spacers, and improved weather stripping. And through the Energy Policy Act of 2005, they may also come with up to $500 in federal tax credit.
Windows give you a lot to think about! But they are an important part of any remodel and can become one of the most beautiful features of your home. As always, we welcome your home architect design questions at firstname.lastname@example.org.