
Fiberglass Windows

Windows That Weather It All
The climate in the Rockies puts windows to the test–scorching summers, freezing winters, and wild temperature swings. Fiberglass windows from Wyoming Building Supply are engineered to handle it all without cracking, warping, or losing efficiency.
Stronger than vinyl and low-maintenance, our fiberglass options deliver lasting durability and energy savings you can count on. Whether you’re remodeling your kitchen or managing a commercial project, our team is here to help you explore the best fiberglass windows for the job. We’ll even install them, ensuring they perform beautifully for decades.
Benefits That Go Beyond the View
Durability
Fiberglass resists warping, swelling, rotting, and corrosion, issues common with other materials in harsher climates. It expands and contracts at nearly the same rate as glass, reducing stress on seals and joints–protecting its lifespan. Our Modern, Elevate, and Essential lines use high-density fiberglass or proprietary Ultrex® material for maximum durability.
Energy Efficiency
Fiberglass frames are naturally insulating and can be filled with insulation for added performance. Tight seals help maintain consistent indoor temperatures, with many fiberglass windows meeting or exceeding ENERGY STAR® ratings. That means lower heating and cooling costs.
Low Maintenance
Unlike vinyl and wood, which can fade, chip, and crack without regular care and periodic maintenance, fiberglass windows maintain their shape, color, and performance with minimal upkeep. With occasional cleaning, you can keep your windows looking brand new.
Customizable
Choose from a wide range of finishes and styles, including options that mimic the look of wood. Thanks to fiberglass’s strength, it supports large glazed areas, making it an excellent choice for kitchen remodels and rooms where expansive views matter.
Environmentally-Friendly
Made from silica sand, a renewable resource, fiberglass requires less energy to produce than aluminum. Plus, thanks to its long lifespan, often 50 years or more, this material option reduces the need for replacements.

Fiberglass Window Installation
Fiberglass windows are engineered for exceptional performance, but they can only deliver that performance if they’re installed with precision. Even a slight misalignment can cause problems over time, such as gaps that let drafts in, seals that fail under the temperature swings of the Rockies, or frames that put stress on the glass.
A flawless fit ensures the frame and glass move together as one, maintaining the airtight seal that gives these windows their superior insulation and energy efficiency. That’s why Wyoming Building Supply offers professional fiberglass window installation services. Our licensed professionals use meticulous measurements, advanced tools, and proven techniques to ensure your windows perform as promised–keeping your home comfortable and your utility bills low.
Fiberglass Windows for Homeowners
Building a new home or making updates? Fiberglass windows are a great option, and a smart choice for larger, unobstructed views, minimal maintenance, and long-term energy savings. Popular styles we supply and install include single hung, double hung, casement, awning, sliding, bay & bow, corner windows, and even specialty shapes.
Fiberglass Windows for Commercial Projects
The strength and consistency of fiberglass makes it a great option for builders and contractors. It allows larger glass sizes, can withstand heavy-use environments, and reduces long-term maintenance costs. Team up with Wyoming Building Supply for reliable delivery and trained installation crews that help your projects stay on schedule.

Why Customers Love Wyoming Building Supply
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From Design to Installation
Design
Collaborate with experts to bring your vision to life with precision and creativity.
Select
Explore our range of quality products tailored to your unique needs and preferences.
Deliver
Enjoy a seamless and efficient in-state delivery process that ensures your products arrive in perfect condition—without paying shipping costs.
Install
Sit back and relax as our experienced professionals transform your space with precision and care.
Serving Wyoming & Beyond
Since 1976, we've proudly served the Rocky Mountain region from our five locations: Casper, Cheyenne, Sheridan, and Cody in Wyoming, plus Rapid City in South Dakota. For your convenience, our service area extends to northern Colorado, southern Montana, and western South Dakota.
Visit One of Our Showrooms
2104 Fairgrounds Road
Casper, WY 82604
Phone: (307) 265-7935
3920 N. College
Cheyenne, WY 82001
Phone: (307) 637-5500
2526 Sheridan Ave.
Cody, WY 82414
Phone: (307) 578-8228
43 E. 5th St.
Sheridan, WY 82801
Phone: (307) 674-4699
1625 Cambell St.
Rapid City, SD 57701
Phone: (605) 416-9377
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Let’s Get Started
Need help with an upcoming project? Ask for a quote, or contact us if you have questions.