Fiberglass vs. Vinyl Windows—What’s the Difference?

Apr 20, 2021

Fiberglass vs. Vinyl Windows Are you living in a home that has aging or builder-grade windows? If so, replacing your windows is one of the best upgrades you can make. Inferior windows deliver subpar insulation and weather resistance, which means your windows could be racking up unnecessary energy and maintenance costs simply by not doing their job to the fullest extent.

However, if you’re like many homeowners, you may find the replacement window market to be a bewildering jungle of options from dozens of window manufacturers, all claiming to make the most beautiful, enduring, and energy-efficient windows a homeowner can buy. As you continue your research, you’ll undoubtedly learn that fiberglass and vinyl are better choices for window frames than wood or aluminum. But why? Because wood-frame windows are vulnerable to rot and termites, which means they’ll require more intensive upkeep than many 21st-century homeowners have time for. And aluminum can’t compete with newer window-frame materials when it comes to beauty or energy efficiency.

So, now that we’ve established that your new replacement windows should have either fiberglass or vinyl frames, what’s the difference between the two?

Brawny & Beautiful—Must Be a Fiberglass Window

Fiberglass window frames are among the most recent advancements in window construction. Their main claim to fame is their outstanding strength, which plays a big role in their energy efficiency, weather resistance, and eye-catching appearance. High-quality fiberglass windows are stronger than their wood or vinyl counterparts, and fiberglass is far less prone to shrinking and swelling during temperature changes. Both of these characteristics mean that fiberglass frames can be remarkably slender and still securely hold a large expanse of glass while keeping the window seal intact. As a result, a well-constructed fiberglass window will:

  • Sport a sleek and sophisticated appearance that will enhance any home’s curb appeal
  • Provide more expansive views of the great outdoors than most other types of windows can
  • Prevent air infiltration, which can undermine energy efficiency
  • Protect your home from water leaks and moisture intrusion, which can lead to mold growth and structural damage

The Virtues of Vinyl Windows

Vinyl has become one of the most popular frame materials for replacement windows, and its superiority over wood and aluminum is practically indisputable. High-quality vinyl window frames will look lovely for many years with no maintenance required apart from an occasional cleaning. Moreover, premium vinyl frames can be engineered to provide exceptional insulation against outside temperatures, and they’re also available with foam insulation for maximum thermal protection. When crafted with energy-efficient glass, vinyl windows are often the ideal choice for homeowners who want to reduce their carbon footprint and keep their heating and cooling costs in check.

Whether you gravitate toward fiberglass or vinyl for your home’s replacement windows, you’ll want to keep in mind that opting for high-quality materials, construction, and installation services will all be important if you want the best bang for your buck.

The experts at Johnson County Siding & Window Co. have been outfitting homes throughout the Kansas City metro area with beautiful, long-lasting replacement windows for more than 40 years. We’ve scoured the market for the best-performing windows to install for our customers, and we’ve chosen to offer windows from two of the industry’s most recognized names: Marvin®, a leader in fiberglass window construction, and ProVia®, an award-winning vinyl window manufacturer. We’ve also gone the extra mile to earn certification credentials from these esteemed manufacturers, which means you can rest assured that any windows you receive from us will be flawlessly installed according to the manufacturer’s specifications.

If you’re planning to replace the windows of your home in the Kansas City area and you’d like to explore the merits of fiberglass vs. vinyl windows even further, contact Johnson County Siding & Window Co. today. We’ll be happy to provide details about our beautiful replacement windows and tell you about the financing options available to qualified homeowners.


If you know you want to get your home exterior project done, but are feeling stress about paying for it all at once, we can help.

Our financing partner, GreenSky, has sensible payment plans that work for homeowners who prefer to pay in installments. You can also ask your JoCo Siding & Window Co. sales representative about the details!

20% Off Your New Siding Plus, 50% Off Home Insulation!

Upgrade to James Hardie Siding Today!

Offer Expires Nov. 30th 2022

Our Customers LOVE The Results

Johnson County Siding & Window Co.
"I enjoyed the experience of Johnson County Siding coming out and going through the process of selecting siding for my house. They send an in depth contract that was spelled out specifically what was going to occur and followed through with everything. I would recommend Johnson County Siding to work on your house.”

- Kyle R.
Johnson County Siding & Window Co.
"We used Johnson County Siding and Window in our previous home about 20 years ago, and were very pleased with their work. So, when we needed new windows in our current home, we knew we wanted to use them again. And we were not disappointed! They were professional and completed the job in the time expected.”

- Don B.
Johnson County Siding & Window Co.
"We are very pleased with our new windows, as well as the overall experience working with Johnson County Siding & Window Company. The communication was excellent and the final product is exceptional. Our installers worked efficiently and kept us updated throughout the entire process.”

- Miles P.

Areas We Serve

Serving the Kansas City Metro Area, Including Olathe, Overland Park, and Leawood See a Full List of the Cities We Serve