Most of today’s windows are made from a frame material and an insulating glass “sandwich”—each component subject to wear, weathering, and potential failure. Weatherstripping in the frame and moving parts can wear out with use. An insulating glass panel may suffer a broken seal after years of expansion and contraction with temperature changes—creating a “fogged” look as moisture accumulates between the glass panels.
Some windows can last up to 50 years. Some of the factors that go into the determination include:
Quality Construction practices and building style
Climate and Exposure
Routine Care and Maintenance
Replacement of parts that wear with Use