In older houses, faulty windows can account for a third of the total heat loss in winter and as much as 75 percent of interior heat gain in summer. Look for the following telltale signs that a window has lost its effectiveness.
- Stand inside your house on a windy day with a lit candle near the window's edge. If the flame flickers or goes out, your weather stripping could be damaged.
- During the winter, if a window experiences ice buildup or a frosty glaze on the interior of the pane, the ventilation in your home may not be adequate. Another possibility is that your window may not be providing enough insulation value, making your heating bills soar.
- If you need to prop open your window with a book or a stick, the window may have lost its functionality.
- Sit near your window. If you feel cold air coming in during the winter or warm air during the summer, your windows have little insulation value. This means you're paying more to heat and cool your house to compensate for the exterior air entering your home.
- Do your windows get fogged with condensation? If so, you may have a seal failure and need to replace the glazing or the entire window.
In some cases, replacing broken panes and tending to loose or missing weather stripping may buy some time. If your windows are old and ill-fitting, however, you need more than stopgaps.
Continued on page 2: Replacement Window Options