Skip to main content

Exit WCAG Theme

Switch to Non-ADA Website

Accessibility Options

Select Text Sizes

Select Text Color

Website Accessibility Information Close Options
Close Menu
Fiberglass Options
A Window For Every Climate

Fiberglass windows and doors provide a strong defense against the random fury of Mother Nature. They maintain their beauty in every season, in any climate. They will not crack, peel, bend, warp, or split. And they are immune to the effects of water, cold, heat, insects, salt air – even ultraviolet rays.

As you search for the right types of window frames to replace your existing units, you’ll find that there are quite a few different options to choose from. Fiberglass framed windows have a number of unique benefits, and depending on your situation, these types of windows might be perfect for your home or commercial application. Learn more about fiberglass replacement windows to decide whether or not these types of window frames are right for your needs.

Key Benefits

  • Superior resistance to weather elements
  • Will not crack, peel, bend, warp, or split
  • Immune to the effects of water, cold, heat, insects, salt air, ultraviolet rays
  • Noise and temperature insulation
  • Eco-friendly, energy-efficient
American Vision Windows 20 Years

Save BIG on new windows!

What Are Fiberglass Replacement Windows?

Fiberglass-framed windows are window frames that are made predominantly from fiberglass. Some of these windows feature an all-fiberglass construction, but others incorporate fiberglass in conjunction with other materials. Vinyl is the main alternative to fiberglass when it comes to window frames, but you may find that fiberglass is an ideal solution in your application due to some of the common shortcomings associated with vinyl windows.

How Are Fiberglass Window Frames Made?

Most of the parts in fiberglass window frames are constructed through a process called pultrusion. Automated machines perform this manufacturing process, and it begins when two types of raw fiberglass called roving and strand mat are coated with a special type of resin.

These resin-covered components are then covered with a fiberglass veil and pulled into a die that hardens the resin with heat. Separate dies are used for each part of a fiberglass window, and once the rigid fiberglass lineal is extruded from the die, it is usually immediately cut to the proper length to construct a window frame of a particular height and width.

Next, these lengths of lineal are fitted with nylon-reinforced corner blocks that can’t be seen on the finished product, and they are then screwed and glued together. Once this process is completed, the joints between different fiberglass lineals are practically indestructible.

Fiber Glass
Benefits of Fiberglass-Framed Windows
  • Energy Efficiency

    Unlike other types of window frames, fiberglass frames don’t expand or contract when the temperature changes. This feature allows fiberglass frames to insulate your house better from extreme temperatures; it’s estimated that fiberglass-framed windows are three times more energy-efficient than vinyl windows since they reduce your heating and cooling costs.

  • Noise Insulation

    Fiberglass blocks noise in the same way that it insulates your home from temperature changes. While other types of window frames might let too much outside noise in, fiberglass-framed windows will be much more effective at blocking out road noise or the sound of your neighbor’s lawnmower.

  • Durability

    Fiberglass is more durable than both vinyl and wood. Some estimates suggest that fiberglass is eight times stronger than vinyl, which may prove to be an important feature if you live in an area that’s prone to natural disasters like hurricanes, tornadoes, or earthquakes.

    Most vinyl windows are only rated to last 30 years, and they will start to peel and crack as they get older. Fiberglass windows, on the other hand, are rated to last 50 years or more, which makes these types of windows the clear winner if you have sustainability in mind.

  • Customizability

    It’s just as easy to paint on fiberglass as it is on wood, and your paint job will last longer if you lay it down on a fiberglass-framed window. Manufacturers of these types of windows often provide a number of color and style options right off the bat, and with a little bit of prep work, you can paint your new window frames like a pro.

  • ECO-Friendly

    While it might not look it, fiberglass is made from glass, which means that it is eco-friendly. Vinyl is toxic, and it can release harmful gases into the atmosphere while it is in use and after it has been discarded. Fiberglass doesn’t have these issues, which might make it the right choice if you want to protect the environment.

  • Aesthetic Appeal

    Vinyl windows have visible join lines at their corners, but fiberglass frames do not. Because of this feature, fiberglass windows are much more capable of mimicking the appearance of a genuine wood frame than vinyl windows. In addition, while vinyl windows can’t be painted, you can paint your fiberglass frames in any color you choose.

Fiberglass vs. Vinyl for Window Frames

While other materials are sometimes used to make window frames, fiberglass and vinyl are the two major competitors. While these frame materials are relatively similar, there are a few key differences between fiberglass and vinyl that you should keep in mind as you pick the right type of frame for your home or business.

For starters, fiberglass costs significantly more than vinyl. Given the impressive benefits of fiberglass frames, this increased financial investment isn’t surprising, but it may make a difference in your calculations. A 48-inch vinyl window usually costs about $520-730, but a fiberglass window of the same size costs anywhere between $580 and $1,700. Installation costs about $250-300 per window for both materials.

In addition, these two types of frame materials age differently. Over time, fiberglass window frames may peel or fade, and you can then repaint your fiberglass frames to make them look like new. Vinyl frames, on the other hand, can warp or contract, which can lead to poor air seals or water damage. In terms of insulating ability, vinyl is not nearly as effective when compared to fiberglass, and this material becomes even more inefficient as it ages.

If you’re wondering which type of window frame provides the best resale value, the jury is still out since fiberglass is a relatively new frame material. However, initial estimates suggest that fiberglass window frames recoup approximately the same value as vinyl window frames.

The only reason that you might want to pick vinyl over fiberglass is if you’re installing your window frames yourself. Vinyl is relatively flexible, which makes it easier to fit these frames into the hole you’ve cut for your window. Fiberglass, on the other hand, doesn’t expand or contract, so you’ll need to make sure that your cuts are very precise when you install fiberglass window frames.

How Does Fiberglass Compare to Other Frame Options?

Besides fiberglass, there are a couple of other types of frame materials to choose from. Neither of these materials is as popular as fiberglass or vinyl for a number of reasons, but it’s important to know about the potential benefits of clad wood and aluminum as you make your decision.

Clad Wood

If clad wood windows were less expensive, they would probably be the most popular types of window frames on the market. These types of windows are about the same as fiberglass in terms of performance and longevity, but they cost 30-50 perfecnt more than their fiberglass counterparts. Clad wood windows are framed with wood, and they have exterior metal surfaces that reduce maintenance costs.


Aluminum window frames are very lightweight, and they are similar to fiberglass in their low maintenance needs and high rigidity. However, aluminum is a great conductor of heat, which means that these types of windows do very little to protect your home from changes in temperature. If you live in an area where seasonal temperature fluctuations are extreme, aluminum windows are the wrong choice.

What Types of Fiberglass Frames Are There?

Now that you understand the benefits of fiberglass window frames, it’s time to pick the right type of frame for your purposes. Here are some examples of popular fiberglass frame styles:

All Fiberglass

As the name implies, these types of windows are made from fiberglass through and through. Their exterior surfaces are coated with a special protective finish, and they can be painted in any color that you choose.

Windows that are made entirely from fiberglass are lightweight, and they are usually less expensive than other fiberglass window options. These types of windows are also highly durable, and they make the most out of the anti-leak and heat conservation benefits of fiberglass.

Wood Interior

If you like the benefits of fiberglass but you’re not sure how fiberglass windowsills and sashes would look in the interior of your home, you might want to have the best of both worlds and pick a fiberglass window with a wood interior. On the outside, these types of windows are 100 percent fiberglass, which protects your home from leaks and temperature fluctuations. On the inside, however, you have your choice of wood types for the interior sills and sashes of your eco-friendly replacement windows.


Some homeowners are more interested in the fact that fiberglass doesn’t expand or contract than they are in any of the other properties of this remarkable substance. In some cases, you may be able to find windows that only incorporate fiberglass in their sashes; this type of construction ensures that the area directly surrounding you window glass won’t contract or expand due to heat or cold, but windows that are made this way miss out on the durability that exterior fiberglass offers.

In most cases, the remaining portions of these types of windows are made from wood. However, wood is susceptible to rot and other forms of water damage, and it isn’t as good of an insulator when compared to fiberglass.

Fiber Glass
Should You Replace Your Windows with Fiberglass Frames?

While installing fiberglass window frames in a new home is definitely a wise choice, installing this type of window make even more sense when you need to replace your existing windows. Whether one of your windows has sprung a leak, a vinyl window has warped out of shape, or you simply want to reduce your heating bills in the winter, replacing your existing windows with fiberglass options might be one of the smartest moves you can make as a homeowner.

As soon as you replace one of your window frames with a fiberglass unit, you’ll notice how much more of the outside is brought into your home. Since fiberglass is stiff and strong without being bulky, the sashes on fiberglass frames take up much less space than the materials you’re used to. Even if you start off only wanting to replace a problem window, after you see your fiberglass frame in action, you may choose to replace all of your windows with fiberglass frames.

As you pick out and install fiberglass window frames in your home, keep in mind that this substance can deteriorate when it is exposed to UV radiation. Therefore, it’s very important to make sure that the factory-applied UV coating on the exterior of your windows is strong enough to do the job right.

What Are the Benefits of Hiring Professionals to Install Your Replacement Windows?

If you’re relatively handy around the house, it might be tempting to install your new fiberglass window frames yourself. However, these types of frames are harder to install than others, and if you make a single mistake, your window could start leaking during the next big storm.

Professional installers have the experience necessary to install your windows flawlessly, and having your windows installed by the pros also frees you up to focus on other concerns. If you only need to replace one window, it might make sense to handle the installation process yourself under certain circumstances, but when you’re replacing multiple windows, relying on a professional installation service is the only way to ensure that your new windows will keep your home leak-free and looking good for the long haul.

Entry Door
Try Fiberglass Windows Today

Learn more about the benefits of fiberglass windows or schedule a FREE no obligation estimate. Make sure to ask about our impressive financing options!

Need help with your new windows or doors?

Share This Page:
Facebook Twitter LinkedIn
Skip footer and go back to main navigation

*Tax based on materials only. On approved credit, not all applicants will qualify. New customers only. Cannot be combined with any other offers. Some restrictions apply.

Call for details. Offer Expires 07/31/24. CSLB# 778326. ROC#267599.