How long does a double-pane insulated window last? 

You can expect double or triple-pane (insulated) window glass to last 10 to 20 years, and an average of about 15 years, until the seal around the glass panes leaks and the inert gas escapes. When this happens, the insulating ability of the window is lost. The window will not look any different at at first, but eventually air flow and condensation in the gap between the panes will allow a layer of dust to accumulate and cloud the window.

    The seal can fail even sooner due to a manufacturing defect or if the window is pressure washed. Also, “thermal pumping” can occur at windows exposed to direct rays of afternoon sun, which weakens the seal. To learn more, see our blog posts How do you keep double-pane insulated windows from from getting cloudy? and Why is pressure washing double pane windows an expensive mistake? and Should I buy a house with double-pane insulated glass windows that are clouded? 

    Here’s a bar graph comparing the life expectancy of double-pane window glass to other window types.
    Go to our blog post What is the average lifespan of the parts of a house? for rating of other house components. To understand the basis, potential use, and limitations of lifespan ratings, see How accurate are the average life expectancy ratings of home components? Are they actually useful? 

    Also, our article What is the average life expectancy of windows? includes an overview of the many factors that affect how long a window lasts.  

  To learn more about windows, see these other blog posts: 

• What are the signs it's time to replace windows?

• How can I tell if a window or sliding glass door is double or triple pane (insulated) glass?

• How can I tell if a window or glass door is safety glass? 

• What is "low-E" window glass? 

• Are openable windows required to have window screens? Will windows with no screens pass a home inspection?

• What does ANSI 297.1 on glass mean?

• Does a home inspector test all the windows and doors in a home? 

• How difficult is it to change a window to french doors or a sliding glass door?

• What are the small slots at the bottom of the outside of my window? 

• Why does condensation form on the outside of some windows and not others in the morning? 

• Why are window security bars dangerous? 

• What is the tempered label on glass at windows and sliding glass doors called?

• What is an egress window? 

   Visit our DOORS AND WINDOWS and LIFE EXPECTANCY pages for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles. 

NOTE: These life expectancies are based on data provided by InterNACHI, NAHB, FannieMae, and our own professional experience. Because of the numerous variables that can affect a lifespan, they should be used as rough guidelines only, and not relied upon as a warranty or guarantee of future performance.