Colorado’s altitude and UV equate to one of the most dramatic weather climates in the country - leading to rapid deterioration of ordinary windows.

So why take a chance with your home using ordinary windows? Introducing Infinity from Marvin Fiberglass Windows

replacement windowsd built for life proof cement

Proven Strength 

The facts prove it. Ultrex fiberglass is eight times stronger than vinyl and three times stronger than vinyl/wood composites. It resists fading, chalking, peeling and cracking, giving you unparalleled strength and durability. We’re constantly testing Ultrex to prove it’s the toughest window material available.

Double Hung Window - 3 Wide Mull


Fiberglass Windows

We know fiberglass windows are the best replacement solution for Colorado's Climate.  But not just any fiberglass.  Our Infinity from Marvin fiberglass window is made from ULTREX.  Marvin's Patented ULTREX fiberglass is the strongest fiberglass on the market.

Ultrex fiberglass - a pultruded fiberglass material




Ultrex pultruded fiberglass, a material patented nearly 20 years ago when Marvin pioneered the fiberglass windows and door category. Infinity windows have led the category ever since with a commitment to a product that is tough, smart, long lasting, and worry-free.


We don’t just claim that Ultrex pultruded fiberglass is the toughest window material available; we prove it. Through a variety of punishing tests in harsh conditions, Infinity windows made with Ultrex comes out on top again and again. Watch this video and see just how tough Ultrex really is!

Built Clean

Ultrex is made from silica sand – a safe and abundant natural resource. The Ultrex manufacturing facilities fully comply with the 1990 Clean Air Act and are designated as a Maximum Achievable Control Technology (MACT) facility as outlined by the EPA.  Read more here

Read more about Infinity from Marvin's Sustainability here






Window Installation

Installation is a key component of your replacement window or door project. At Gravina's Window Center of Littleton, we know that Poorly installed windows will cause even the highest quality windows to underperform. You will find our technicians to be knowledgeable, courteous, skilled, true craftsmen, easy to work with and willing to work hard to see that your project exceeds your expectations. Also, we have Installation Masters Certification, so we are experts when it comes to different home applications.

"Beautiful windows designed and made with the power of fiberglass"