Infinity® by Marvin®: The Ultimate Fiberglass Replacement Windows
You deserve windows that not only stand the test of time but that stay true to the look and feel of your home. C&T Siding delivers by offering Infinity® by Marvin® windows coupled with our unbeatable service. From helping you select windows that fit your home to filling every nail hole, we’re here every step of the way.
Fiberglass windows can withstand even the harshest Minnesota and Wisconsin winters, keeping your family comfortable all year long. Fiberglass outlasts vinyl, aluminum and fiberglass composites. Constructed using Ultrex® fiberglass, Marvin windows consistently meet or exceed regulations for residential windows.

Why Choose Fiberglass Windows?
Thermal Performance
Ultrex® fiberglass windows meet or exceed ENERGY STAR guidelines. They keep out wind and moisture while protecting your home from hot summers and the coldest of winters. You’ll notice the difference in your energy bills each month.
Unbeatable Strength
Ultrex® fiberglass is eight times stronger than vinyl and three times stronger than vinyl/wood composites. There’s no need to worry about fading, chalking, peeling or cracking. Plus, there’s zero maintenance required.
Appearance & Design
Choose from a variety of window design options for both traditional and modern homes. Our windows feature the strength of fiberglass combined with popular style and design options, including divided lites and grilles.
Built For Midwest Winters
Fiberglass windows expand and contract at a slower rate than other materials such as vinyl. This means they reduce the risk of air leaks that can cause chilly drafts.
Total Design & Install
Our windows are designed with the features and options to fit your lifestyle. They’re also built to your specifications and delivered to your home ready to install. We take care of everything so you don’t have to.
Lifetime Transferable Warranty
Our fiberglass windows are backed by a 20-year warranty on glass seals and a 10-year warranty on manufacturer defects. Plus, we warrant our workmanship for the lifetime of your product. Transferable Life time warranty on manufacturer defects. 20 year warranty on glass.
Reliability & Expertise
For over 45 years, we’ve been dedicated to ensuring homeowners receive the best fiberglass windows and service available. You can trust us to deliver a beautiful finished product you can be proud of.
Beautiful Windows—Inside & Out
Custom Millwork to Match the Style of Your Home
With an on-site mill, we can match your new window trim to the trim within your home. Before we install your new windows, we remove a piece of trim, take it to our shop and mill the rest of your trim for a perfect fit.
Infinity® from Marvin® offers Everwood, a stainable fiberglass interior. If you choose Everwood, we’ll take your trim and stain to ensure your window’s interior color matches, too.
Pre-Stained or Painted Trim Gets the Job Done Faster
If you choose one of Marvin’s window color interiors, we custom stain or paint your window trim to match. We do this once inside our shop and apply the final coat after installation. This includes filling every nail hole and caulking the edges for a seamless look.

Get Inspired by Our Work
Since 1978, the C&T Siding team has been helping homeowners refresh their homes with new windows. We’ve completed hundreds of projects throughout Minneapolis/St. Paul and western Wisconsin. Check out some of our recent projects to help inspire your own.


Frequently Asked Questions
How much does a fiberglass window cost?
Fiberglass windows are the best windows available for your home. Cost depends greatly on the size of the window and design choices. The average cost of a fiberglass window is around $3,000.
How long will fiberglass windows last?
Fiberglass windows will last about 30 years with proper installation and care. They’re the longest-lasting windows available on the market today.
Are fiberglass windows better than wood?
Yes. Wood will deteriorate over time, especially in the harsh Upper Midwest elements. Fiberglass windows expand and contract slower than other materials. This means they help prevent air leaks that cause chilly drafts and cool air loss—something wood cannot do.
Can you paint or stain fiberglass windows?
Yes. We’ll work with you to custom paint or stain your fiberglass windows to match the interior of your home.
Do fiberglass windows fade?
If your fiberglass windows have an acrylic finish, they will fade very little over time. At C & T Siding, we finish our windows in this way to help improve their longevity.
Are fiberglass windows energy-efficient?
Fiberglass windows have zero conductivity. This means they’re the most energy-efficient windows on the market. They expand and contract at a slower rate, preventing heat loss in the winter and cool air loss in the summer.