Windows / Fiberglass Windows / Marvin Integrity

Marvin Integrity Windows

Marvin Integrity Windows

The Marvin brand has two lines of windows and doors: Marvin and Integrity.

The main difference between our Marvin and Integrity lines is that our Integrity line utilizes a pultruded fiberglass material called Ultrex which is a very durable energy efficient strong green material that is either available with the wood interior or an all fiberglass window.

Ultrex is a supertough polymer of glass fibers and polyester resin that is so hard, diamond-edged blades are needed to cut it. Used on the space shuttle, Ultrex creates an unyielding structural backbone for every Integrity door and window, as well as the weather-proof exterior.

All window types are available in many standard sizes with a choice of three exterior finishes. Integrity windows are able to offer both performance and beauty because of a revolutionary material created to be virtually impervious to the ravages of time, heat, cold, and pressure.

Marvin Integrity Fiberglass Windows


Marvin Ultrex Series
All Ultrex Series

Combining Ultrex with classic wood interiors, Integrity windows are low-maintenance and long-lasting. Ultrex along with a high-performance acrylic coating make it resistant to cracks, scratches, and dents. Ultrex stands up to everyday challenges and maintains a flawless appearance for years.


Marvin Wood-Ultrex Series
Wood-Ultrex Series

Wood-Ultrex Series windows and doors feature exteriors of Ultrex fiberglass and beautiful real wood interiors. Setting new standards in low maintenance and top aesthetics, Integrity Wood-Ultrex series combines the most popular sizes and styles of windows and improves them with Ultrex durability.


Ultrex gives builders products that are...
  • Unyieldingly Tough - Ultrex is 8x stronger than vinyl, 3.5x stronger than wood/vinyl composites and even 2x stronger than steel.
  • Uncompromisingly Strong - Ultrex is the ultimate in strength when it comes to window frame materials - one-square inch can hold the weight of 20 cars.
  • Incredibly Stable - Ultrex's expansion and contraction rate is the same as glass, which is 833 percent less than vinyl (per 50 degree Fahrenheit temperature change) and allows the overall unit to remain tightly adhered. No cracks in the material or leakage around the glass mean no call-backs.
  • Covered With a Patented Finishing Process - Applied through a patented coating process, Ultrex's durable, high-performance finish is up to 3x thicker than vinyl's and other composite windows. Thanks to Ultrex, Integrity windows and doors are virtually indestructible from warping, dents, dings and scratches, as well as UV rays that can cause fading.
  • Precisely Constructed - Corner keys and Ultrex construction keep it square while keeping air and water out. A sloped sill design sheds water better than weep holes that can plug and back-up.
  • Time-Tested - Jobsites and Mother Nature have tested Ultrex's strength and durability each and every day for more than a decade. Whether it's enduring shipping and installation or brutal temps, wind and rain, the result is flawless performance and lasting beauty.
  • Heat-Resistant - Ultrex provides outstanding resistance to distortion even at temperatures up to 350F.

April - Special Offer

Marvin Integrity

50% Off for Limited Time!

Starting from
$998 $499*
per window

Or call us for help:
1-855-355-0515
Your Promo Code is:

* Restrictions and conditions apply. Offer not available in all areas. Advertised discounted price, requires purchase and installation of 7 or more windows. Offer discount is calculated based on lowest priced window product. Cost of installation is excluded from the Offer. Minimum job size is 4 windows.