Marvin Fiberglass Windows

Marvin is the leader in fiberglass, which outlasts vinyl windows by 38%. Our pultruded fiberglass remains stable in extreme temperatures and expands at nearly the same rate as glass.


Infinity windows and doors make the perfect home for any weather! Thanks to Ultrex®, an innovative pultruded fiberglass with acrylic capping, plus a specialized manufacturing process, you can be sure your home is protected from heat or chill. Plus, it won’t wear out – no matter what Mother Nature throws at you!


Infinity’s Ultrex fiberglass windows are truly one-of-a-kind! They have the classic and timeless beauty of warm wood interiors and an enduring strength that surpasses vinyl, roll-form aluminum, and other composites – even in extreme conditions. With Ultrex, you get unbeatable performance for years to come!