Crafted with Ultrex® – the PERFECT window material

Infinity from Marvin® uses fiberglass for unmatched window performance. But that’s only the beginning.

Replacement windows have always been Infinity's sole focus.  They pioneered the use of materials like fiberglass that simply outperform and outlast other options. However, Infinity goes even further with Ultrex® — the proprietary fiberglass solution that offers unsurpassed durability and timeless style.

Gravina’s Window Center of Littleton proudly uses Infinity® Replacement Windows from Marvin® for a hassle-free experience that’s designed to exceed your expectations. So whether you want a simple replacement option or are interested in exploring new possibilities, we’re ready to build a solution for you. For window replacement, the only window you should choose is the Infinity fiberglass window.  It's Marvin's premium full frame replacement window made from Ultrex fiberglass.  Ultrex is patented by Marvin Windows and Doors and is the most durable window material on the market.

Crafted with Ultrex® – the PERFECT window material

Infinity's  Ultrex fiberglass is designed by the experts at Marvin Windows and Doors. Infinity products are made for the homeowner who wants low-maintenance replacement windows with the traditional appearance of a wood window.  At Gravina's, all Infinity products are sold as a complete, installed package to provide you with a high-quality, hassle-free experience.

Ultrex Fiberglass is 8X Stronger Than Vinyl!

Don’t worry. Ultrex can take whatever Mother Nature dishes out because it’s pultruded fiberglass, a material used in products where strength and durability are required. In fact, it’s such a solid, long-lasting material that it’s been used in bridge construction.


Ultrex fiberglass marvin windows replacement


Tough Colorado Climate?

Scorching summer heat or freezing winter temperatures – wherever you live, whatever the climate, Infinity from Marvin replacement windows are outstanding performers.


Our Infinity windows and doors are made of fiberglass and are suited for Colorado's weather.  We hear all the time about homeowners who have vinyl windows in their home and they are leaking and sagging in under 10 years.  So vinyl windows may be cheaper to start, but in the long run, you most likely will have to service and replace them again.  This costs you more so you might as well invest in a better window from the start.

Energy Savings

Infinity windows can cut heating and cooling costs by 11 to 37 percent.*   This is why we don't sell 50 lines of windows.  We trust fiberglass in Colorado, plain and simple.  We have the track record to prove it too.  As one of the oldest fiberglass window dealers in the country, we have had the opportunity to see how durable fiberglass is in our climate.  Unlike vinyl or wood, with Infinity you only have to replace your windows once, saving you more money in the long run.

Local Window Replacement in Denver

We are a local, family-owned small business and have been serving homeowners throughout Colorado since 1973.

*Source: Efficient Windows Collaborative





Infinity Product Catalog

Options and sizing for Infinity windows and doors.

(40 pages)