Fiberglass or vinyl windows – GreenBuildingAdvisor

I’m remodeling my forever/retirement lake house in climate zone 6/7 and trying to decide on vinyl or fiberglass windows.

From research there are vinyl window companies that outperform, objectively speaking fiberglass in DP, U factor, air infiltration, CR rating, warranty.

However, I see fiberglass praised quite a bit.  Empirically speaking I know people who have 25-year-old vinyl windows and look and perform flawlessly (yes if you rub your finger on the exterior, it is chalky), several vinyl window companies have a lifetime warranty. While Marvin fiberglass for example only has a 10 year on the frame and exterior finish. Not to say it won’t last longer but seems pretty short.

While others building passive homes aiming for longevity and energy efficiency are putting in UPVC windows as well as fiberglass.

What’s your thoughts?

Thanks