I believe that a new window can last a lifetime. But realistically, with changing weather and other factors, the likelihood is that it’ll last 30 to 50 years. You can always change the style beforehand, say if you want a new color or a new frame but for the most part, if you don’t touch your windows, change or replace them, or damage them, they will most likely last 30 to 50 years, or it’s possible that they can last longer. Let’s just say: a really long time.