Windows last 15 to 30 years on average, depending on the material and brand. Window warranties typically last 5 to 20 years, although some are covered for as long as you own your home. Consider replacing windows if you notice any of these signs:
Difficulty opening or closing the window
Visible damage, such as a rotting frame or cracked glass
Condensation between window panes
Drafts around the windows
Increased energy bills
The windows are more than 20 years old.