Fiberglass windows are becoming increasingly popular for their top-notch insulation, easy upkeep, and aesthetically pleasing curb appeal. These windows, made from a mixture of cured glass fiber and resin, resemble real wood frames for a classic look. Meanwhile, they provide far better energy efficiency and weather resistance than vinyl or wood windows.
Are fiberglass windows the best windows for your home? I’ll discuss the important cost factors and features you need to make an educated choice.
4.3
Offers wood and vinyl framing options
Excellent customizability
7 glass options
4.0
Low pricing
Lifetime labor and material warranty
Custom financing
How Much Do 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.
| Low-end Cost Range | $400–$650 |
| National Average Cost Range | $750–$1,100 |
| High-end Cost Range | $1,200–$2,000 |
| Extreme High-end Cost Range | $2,500+ |
I retrieve cost data from RSMeans, 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.
| Type of Window | Average Cost Range |
| Single-hung window | $400–$600 |
| Double-hung window | $500–$1,500 |
| Awning window | $500–$1,150 |
| Casement window | $600–$1,400 |
| Picture window | $600–$1,600 |
| Sliding window | $850–$1,100 |
| Garden window | $800–$2,200 |
| Bay/bow window | $900–$2,400 |
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.
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.
My RSMeans 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 Size | Average 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.
Read Also: The Cost of Awning Windows
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 Brand | Average 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.
Find Window Cost Estimates In Your State
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?
I 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.
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:
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.
