Marvin vs Renewal by Andersen: What the Published Specs Say

Marvin and Renewal by Andersen each build around a single proprietary material, Marvin with Ultrex fiberglass and Renewal with Fibrex composite. This page reports what each company states on its own site so you can see the contrast on paper.

How to read this comparison

The facts below come from each company's own website, which is a primary source for what it builds but also marketing. Treat material claims as positioning rather than independent test results. For the energy numbers that matter, U-Factor, SHGC, and Air Leakage, read the NFRC label on the exact product and glass package you are quoted. We do not name a winner.

What Marvin publishes

Marvin builds around Ultrex pultruded fiberglass. The company states that Ultrex and Marvin High-Density Fiberglass are created through a process called pultrusion, and that Ultrex fiberglass is 8x stronger than vinyl and 3x stronger than wood/vinyl composites.

Marvin also cites thermal stability, stating Ultrex fiberglass can withstand extreme temperatures up to 285 degrees Fahrenheit while keeping its shape, and offers its windows in fiberglass, aluminum, and wood.

What Renewal by Andersen publishes

Renewal by Andersen builds exclusively from the Fibrex composite. The company states its windows are made from the Andersen-exclusive Fibrex composite material and frames the product around efficiency, strength and durability, maintenance, and beauty.

Renewal offers that single material across the common styles, listing awning, bay and bow, casement, double-hung, picture, sliding, and specialty windows, and backs them with a limited warranty.

Where they differ on paper

The documented difference is the material class. Marvin builds from pultruded fiberglass and quantifies its strength against vinyl and wood/vinyl composites, while Renewal by Andersen builds from a wood-fiber and thermoplastic composite it calls Fibrex. One brand offers three materials in total; the other builds solely from its single composite.

Both sell through service-oriented channels and both back their products with limited warranties. Because both sell certified products, the decisive energy numbers come from the NFRC label on the exact model and glass package you are quoted.