Fibrex® Composite Material

An Andersen Exclusive

Our revolutionary Fibrex composite material combines the strength and stability of wood with the low-maintenance features of vinyl.

Andersen Corporation created Renewal by Andersen to change the window replacement industry – not only with a different and better process – but also with an innovative new material to make the frames. In 1992, Andersen perfected and patented Fibrex® composite material technology.

Fibrex® material is a better window framing material for several reasons:

  1. Because it is a composite using real wood fiber, it is very strong. This means narrower frames which, in turn, means more glass area. Vinyl frames are often thicker, reducing glass area.

  2. As a low-maintenance composite, it expands and contracts very little, even with extreme temperature swings. This means we can offer dark exterior colors that vinyl can't because Fibrex® material can "take the heat" (150°F).

  3. Due to this material difference, Renewal by Andersen can offer one of the best window limited warranties in the industry.*

Consider everything you expect from a window. Fibrex material makes a difference in every instance. Measured across a range of conditions that affect efficiency, maintenance and beauty, Fibrex material performs well compared to wood, aluminum and fiberglass, and especially well against vinyl. 

 Download our Fibrex® material brochure to learn more about this amazing material.

* See limited warranty.

Fibrex® Material
Other Materials
Because Fibrex® material is strong, we can make our sash and frames narrower.Narrower frames mean more glass, more view.
Vinyl frames are known to have a higher expansion/
contraction rate and can bow, breaking the glass seal.
Fibrex material has superior thermal insulating properties. Combined with Andersen® High-Performance™ Low-E4® glass, this helps your home stay warmer in winter and cooler in summer. You can save money on your energy bills. Your home feels more comfortable.
Aluminum window frames conduct heat and cold.
Heat leaks out of your house in the winter and into
your house in the summer.
Low Maintenance
Fibrex material never needs scraping or painting. It won’t rot, decay or mold.*
Fiberglass frames are painted and may need
regular maintenance.
Renewal by Andersen replacement windows preserve the architectural beauty of your home. Frame and sash design reflect the shape and lines of your original windows. The unique extruded Fibrex material can be made into any kind of window – including curved specialty windows.
Most replacement windows have square profiles that
may look artificial in your home. Vinyl frame material is
often thicker, reducing glass area. Fiberglass can only be made into straight lineals.
Environmental Responsibility
40% of the raw material by weight used to make Fibrex material is clean, reclaimed wood fiber. Reclaimed materials in the manufacturing process can also be reground and reused. Renewal by Andersen® windows are ENERGY STAR® qualified for meeting strict energy efficiency criteria set by the U.S. Department of Energy.
Fiberglass is a thermoset material and cannot be reformed into new profiles.
A window is not just glass and some framing material. It’s a precise combination of glass, frame and quality installation. We back it all with a 20/2/10 Limited Warranty* that is one of the best in the business.
More than half of all remodeling firms have been in business less than four years.** Installation is rarely covered in the written warranty.

Learn more about Fibrex, the exclusive composite material that makes Renewal by Andersen windows a better choice.

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$330 Off Each Window and $725 Off Each Door*

PLUS 12 Months $0 down, 0% interest, and $0 monthly payments*

Offer ends 07/31/2021

Minimum purchase of 4. Interest is billed during the promotional period, but all interest is waived if the purchase amount is paid before the expiration of the promotional period.


Happily Married couple talking to a sales rep at Renewal by Andersen during their virtual consultation
Step 1

Design Consultation

Our design consultants provide in-home or no-contact virtual meetings to listen to your design needs and provide a plan to improve your home.

Our Hassle free process step 2 - MEASURE & MANUFACTURE
Step 2

Measure & Manufacture

Project Technicians ensure accuracy and answer any last minute questions before sending in the order for your fully customized windows.

Our Hassle free process step 3 - INSTALLATION
Step 3


Our Installers treat your home as if it were their own and clean up afterwards.

Our Hassle free process step 4 - CUSTOMER CARE
Step 4

Customer Care

A robust limited warranty is backed by a commitment to making sure your windows function as expected.