Why Integrity Fiberglass Windows and Doors?

Built Tough

Our windows are Built to Perform® in the face of Mother Nature’s toughest elements. The Ultrex pultruded fiberglass that goes into every Integrity window and door remains stable in extreme temperatures and expands at nearly the same rate as glass, resulting in windows that are strong and true. Fiberglass windows have a 38% longer* useful life expectancy than vinyl.
Why Ultrex?

Certified And Unmatched

Ultrex® fiberglass leads the industry in third party finish ratings. Ultrex, with its patented finish, is the first and only fiberglass finish to be verified to any of AAMA’s 624-10 finish specification for fiber reinforced thermoset profiles (fiberglass). This means you can count on Ultrex to resist fading, chalking, cracking, and peeling to keep your home looking great for years to come.
Learn More

Excellence In Efficiency

Our windows and doors are more than just tough, they’re also energy efficient. Integrity products meet or exceed federal ENERGY STAR® guidelines. So with Integrity windows and doors, not only will you reduce your environmental impact, but you’ll also see significant savings on your heating and cooling bill over time.
Learn More

Options That Differentiate

Integrity offers a variety of options that can enhance the look of both traditional and contemporary design. Our All Ultrex and Wood-Ultrex product lines feature the strength of Ultrex pultruded fiberglass and offer a complete line of popular styles and design options, including divided lites and exterior trim.

Superior Service

We are dedicated to leading the way in innovation and never forget the cornerstones of our business. We are highly selective in choosing our business partners—including independently-owned dealers and distributors—to ensure our customers have the best experience possible.
Visit Our Resource Center

The Value of Performance

Integrity windows and doors are Built to Perform® with the features and options to fit your unique project. Our focus is providing high quality products built to your specifications and delivered to your local distributor in an industry-leading 10 days. We use Ultrex pultruded fiberglass to build long-lasting, beautiful windows and doors backed by our never wavering focus on customer service, and a 20-year warranty on glass seals with a 10-year warranty on manufacturer defects.

A History of Innovation

“At Integrity from Marvin Windows and Doors, we didn’t join the fiberglass windows and doors industry – we pioneered it. In 1994, Integrity was born from The Marvin Companies’ century-long heritage of service, craftsmanship and quality with a focus on all-out performance.” – Susan Marvin

Find the perfect window or door

Integrity's windows and doors are made with Ultrex Fiberglass, an innovative material created over 20 years ago. For two decades now, Ultrex has outlasted and outperformed the competition on virtually every measurable scale.