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How Much Do Fiberglass Windows Cost?

Average Cost Range $750–$1,100
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Updated On

September 3, 2025

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Fiberglass windows are a durable and energy-efficient option, with installation costs typically ranging from $750 to $1,100 per window. Known for their excellent insulation, low maintenance, and timeless curb appeal, these windows are crafted from a blend of cured glass fiber and resin that mimics the look of real wood. Unlike wood or vinyl, fiberglass offers superior weather resistance and long-term performance, making it an increasingly popular choice for homeowners.

Are fiberglass windows the best windows for your home? We’ll discuss the important cost factors and features you need to make an educated choice.


Average Fiberglass Windows Cost

Fiberglass windows typically cost $750 to $1,100 per window for materials and installation. However, fiberglass windows may fall far below or above that range due to many cost factors. Smaller, lower-end fiberglass products may start around $400. In contrast, more complex installations or multiple-window projects can rise above $2,000.

Product TypePrice Range
Low-End$400–$650
National Average Cost Range$750–$1,100
High-End$1,200–$2,000
Extreme High-End$2,500+
Cost data retrieved from a project estimation database for contractors. The figures in this article cover rough material and installation costs.

Curious about the technology behind fiberglass windows? This video from Pella Windows and Doors explains how it designs fiberglass windows for superior strength and durability:


What Factors Affect the Cost of Fiberglass Windows?

Many fiberglass windows fall within the average price ranges listed above; however, they’ll likely fluctuate depending on your desired product. You can determine more specific pricing for your fiberglass window project by considering these factors:

  • Window type
  • Window size
  • Window brand

The following sections cover these factors in more detail to help you budget for your new fiberglass windows accordingly.

Read also: Vinyl vs Fiberglass windows: Which is better?

Cost of Fiberglass Windows by Type

The fiberglass window style you need is a good indicator of your starting price. Windows come in wide varieties — double-hung, casement, awning, etc. — each with its own pros, cons, purposes, and price points.

Window TypeLow-End CostHigh-End Cost
Storm$100$400
Single-hung$200$400
Double-hung$430$915
Awning$430$830
Egress$300$1,500
Glass block$500$1,000
Casement$500$1,000
Picture$700$1,300
Sliding $850$1,110
Bay $1,000$7,000
Bow$2,000$4,000

Here are some brief descriptions of the most popular window types. Each style can be constructed with fiberglass framing.

  • Single-hung windows have a fixed upper sash and an operable bottom one that slides up to open.
  • Double-hung windows have two operable sashes that slide or tilt to open, providing ventilation through the top and bottom sections of the frame.
  • Awning windows are hinged at the top and open outward, forming a small glass awning.
  • Casement windows open outward like a door on its hinges. They typically operate via hand crank and seal tightly shut when closed.
  • Picture windows, also called fixed windows, don’t open or close but instead serve to frame outdoor scenery and improve indoor lighting.
  • Sliding windows glide open horizontally and overlap, similar to sliding patio doors.
  • Garden windows protrude outward, forming a small greenhouse-like box perfect for growing indoor plants and herbs.
  • Bay and Bow windows bow out past the side of the home to form a small interior nook. They feature three to five individual window panels and structural work, leading to higher costs. Our article provides detailed information on bow window pricing.
bay window with green cushions
Image Credit: Brooke Aitken Design, Pinterest

Cost of Fiberglass Windows by Size

Size significantly impacts the cost of any window, and fiberglass windows are no exception. You’ll typically pay more for a larger window since it uses more material. However, standard-size fiberglass windows may be cheaper than custom or less popular sizes — even if they’re larger.

Our research yielded specific cost information for various single-hung fiberglass window sizes, and as you can see, standard sizes can be less expensive, even when larger*:

Fiberglass Window SizeAverage Cost
18” X 24”$163
18” X 40”$569
24” X 40”$405
36” X 36”$351
36” X 48”$505
36” X 60”$356
36” X 72”$493
48” X 40”$493
*Single-hung windows are some of the cheapest options available. Other styles cost far more than the figures above, which exhibit how size specifically affects pricing for a particular window type.
Today’s Homeowner Tip

As you can see in the table above, larger windows sometimes cost less than smaller ones. This likely stems from bigger windows coming in standard shapes and sizes that companies prefabricate in bulk. A money-saving rule of thumb for window shopping is to always go with the most standard option available. This will save you from paying custom window prices and add-on labor fees for complicated installations.

Cost of Fiberglass Windows by Brand

Although many popular window brands specialize in vinyl replacement windows, several are venturing into fiberglass products to give customers higher-end, better-performing options. Fiberglass is already one of the most expensive window materials available, and brand overheads can hike the price even higher. However, some brands are still more affordable than others, so you should explore multiple options to find your best fit.

Here are some fiberglass window options and prices from well-known manufacturers below:

Window BrandLow-End CostHigh-End Cost
Pella Impervia®$700$1,000
Kolbe Forgent® Series$725$1,500
Marvin Elevate® Collection$800$2,500
Milgard C650 Ultra™ Series$875$1,900
Andersen A-Series*$1,600$3,400
*Andersen A-series have patented Fibrex® material frames containing PVC resin, wood fibers, and fiberglass. This may not be the right choice for shoppers seeking 100% fiberglass windows.

Additional Costs of Fiberglass Windows

You may encounter additional costs throughout the buying process, regardless of what style or size of fiberglass window you select. Factors like labor fees, project size, customizations, and glazing can add hundreds of dollars to your final price.

Account for the following factors while building your budget:

  • Window installation costs will account for a part of your final bill. Labor fees typically range from $40 to $60 per hour per crew member for fiberglass window installations. Depending on the number of windows you need or the project’s complexity, this could add hundreds of dollars to your final cost.
  • The number of windows you need has the potential to multiply your cost. However, some companies offer bundle deals to lower multi-window replacement costs, making it more affordable to upgrade all of your home’s windows at once.
  • Window customizations like grids, shapes, finishes, frame colors, and custom hardware will up your costs. Tailor-made fiberglass windows take more time and money for window companies to produce, so expect to pay higher retail prices for these options.
  • The glass or glazing of your fiberglass windows is another cost factor to consider. Single-pane windows are the cheapest but provide the fewest benefits. Double and triple-pane windows cost more ($400 to $3,540) but improve your comfort and yield energy cost savings. Many insulated windows contain air or argon gas fills to strengthen the barrier between the glass panes. You can also choose Low-E coated or UV-resistant glazing to enhance your home’s energy efficiency.

How Does the Cost of Fiberglass Windows Compare To Other Window Materials?

Fiberglass is one of the more expensive frame materials for residential windows. See how it compares to other common materials for standard residential windows.


Is DIY Worth the Cost Savings of Installing Fiberglass Windows?

We don’t recommend installing your own fiberglass windows unless you have extensive window experience and knowledge. Window replacements involve opening up your home to the elements. Even if you replace the window quickly, you could do so incorrectly, leaving your indoor spaces susceptible to leaks, drafts, pests, and temperature fluctuations. Avoiding water damage and future window repair costs is worth the price of hiring a professional window installer. And DIY window replacements could present safety risks, especially if you need to work on a ladder.

It’s best to get quotes from several trustworthy companies to find one that fits your budget and needs. Full-service window replacers carry the process from consultation to installation, ensuring your home improvement project is successful and stress-free. You’ll also get a warranty for the window materials and installation, potentially covering repair or replacement costs if issues arise.

Today’s Homeowner Tip

Window warranties vary by manufacturer, installer, and product line. Many installers also have separate warranties for each window series or material they offer. Before buying, read the fiberglass-specific warranty for your chosen provider to ensure you get sufficient coverage for your investment.


Are Fiberglass Windows Worth It for Your Home?

Fiberglass is a high-quality window frame material that can boost your home’s curb appeal, energy efficiency, and weather protection. Although the material comes at a higher price than vinyl and aluminum, its benefits make it a worthwhile investment for many homeowners.

See also: Common issues with fiberglass windows

With the cost factors of fiberglass windows in mind, you’re ready to start shopping. Use the form below to get estimates from local installers:

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FAQs: Cost of Fiberglass Windows

How long does it take to install a fiberglass window?

It takes about an hour for a professional window crew to install one fiberglass window.

Are fiberglass windows stronger than vinyl windows?

Fiberglass is eight times stronger than vinyl and has a life span of up to 50 years. Unlike vinyl, fiberglass won’t warp or crack under fluctuating temperatures, making it ideal for homes in extreme climates. The material also insulates 15% better than vinyl, potentially saving you more on energy bills in the long run.

What are the advantages of installing fiberglass windows?

Fiberglass replacement windows are a solid investment for many homeowners. Fiberglass windows offer superior energy efficiency, insulating your home from fluctuating outdoor temperatures, which can help reduce your energy bills.

Fiberglass windows are also low maintenance and require minimal care to keep them looking new. As part of its low-maintenance appeal, the material is weather and pest-resistant, protecting it from many things that would ruin wooden windows.

Finally, fiberglass windows are customizable. They come in various styles and color options, allowing you to select a look that increases your home’s curb appeal.

What are the drawbacks of fiberglass windows?

The main downside of fiberglass windows is their high price, which results from increased demand, limited availability, and raw material costs.

Although fiberglass windows are considered maintenance-free, you may need to freshen them up now and then. Some homeowners paint their fiberglass windows or add protective coatings to prevent scratches and nicks. In extremely sunny climates, fiberglass windows may show signs of fading over time. These factors are drawbacks for homeowners seeking a true maintenance-free window.

Some homeowners also note that fiberglass windows are prone to water leaks. Fiberglass windows have small gaps between the edges of the window panels, which can lead to leakage from improperly sealed frames. Having a certified installer replace your fiberglass windows is the best way to avoid this issue.

Editorial Contributors

Amy DeYoung

Contributor

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Full Bio

Amy DeYoung has a passion for educating and motivating homeowners to improve their lives through home improvement projects and preventative measures. She is a content writer and editor specializing in pest control, moving, window, and lawn/gardening content for Today’s Homeowner. Amy utilizes her own experience within the pest control and real estate industry to educate readers. She studied business, communications, and writing at Arizona State University.

Lora Novak

Senior Editor

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Full Bio

Lora Novak meticulously proofreads and edits all commercial content for Today’s Homeowner to guarantee that it contains the most up-to-date information. Lora brings over 12 years of writing, editing, and digital marketing expertise. She’s worked on thousands of articles related to heating, air conditioning, ventilation, roofing, plumbing, lawn/garden, pest control, insurance, and other general homeownership topics.
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