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Replacement Windows Denver

303-794-0490   SHOWROOM HOURS: Monday - Friday 8am - 5pm; Saturday 9am - 3pm  (After hours by appointment)

We are THE experts in fiberglass window installation!  

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most durable window on the market 

Denver Weather – no worries

Ultrex PULTRUDED fiberglass resists the ravages of cold, heat, time and pressure to provide the most worry-free windows and doors available today. While vinyl can distort in extreme heat or streak and crack in the fluctuating temperatures, Infinity products offer the highest level of performance and are virtually maintenance-free.


Ultrex fiberglass is 8X stonger than vinyl

Ultrex Fiberglass from Marvin has an extremely low thermal expansion rate, which keeps the window stable and weathertight, reducing the risk of seal failures and air leakage into your home.

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Tired of windows that are difficult to operate?

The low expansion of Ultrex means Infinity Windows resist sticking, swelling, and warping, providing easy operation for the life of the window.



Are you sick of high-maintenance windows?

The low expansion of Ultrex fiberglass means Infinity’s patented finish stays looking like new and is virtually maintenance free. It resists discoloring, warping, rotting, corrosion, denting, rust and doesn’t require sanding, scraping, or painting...which, in Colorado, is a headache.


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The difference is in the details

Vinyl windows can arrive with messy welded corners, and bulky profiles that reduce your view. Infinity windows arrive with clean mechanically-bonded corners, traditional details, and narrow profiles to maximize your view.

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Window durability - Built for a lifetime

Ultrex is as strong as low carbon steel and 8x stronger than vinyl. It's so tough we have to use diamond-edge blades just to cut it to size. The strength of Ultrex translates into superior stability, long-term ease of operation, low-maintenance, and superior performance.


At Gravina's Window Center of Littleton we strive to make every project we undertake easy and enjoyable for our customer. We pride ourselves on the honesty and integrity of every member of our family, from our crews all the way up to our owners. We use only the highest quality materials to provide professional home improvements to our neighbors in the Littleton and Denver areas.



Start your window replacement project today!

Simply fill out the contact form or call us at 303-794-0490 for your free no-obligation quote.

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 Professional Window Installation from our own certified installers!

Window Installation Denver


Visit Our Littleton Showroom - 89 W Littleton Blvd., Littleton, CO !

  • Windows

    Replacement windows add value and beauty to your home, reduce costly maintenance, and save you money on your utility bills. Read More
  • Entry Doors

    Gravina's recommends Therma Tru entry doors for long-lasting beauty and value with less maintenance. Read More
  • Patio Doors

    Patio Doors need to withstand heavy use as well as our extreme weather conditions here in Colorado. Read More
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   Family Owned Since 1973, Serving the following areas:

Denver | Littleton | Wheat Ridge | Lakewood
Englewood Centennial | Highlands Ranch
Westminster | Parker | Boulder | Broomfield, Co
 | Aurora | Golden | Castle Rock

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