Enter your zip to
find local pros.


Fiberglass Windows

Average cost range:

$340 - $720

As of 2022, the average cost to install fiberglass windows is $340 to $720 per window, with a national average cost of $530 per fiberglass window. This average price includes the cost of both materials and labor. Keep in mind that replacement costs can go up to $950 for higher-end window styles. Fiberglass windows are usually more expensive than vinyl windows (which average $260 to $550 per window).

Find the best window contractors in your area.

Replacement Fiberglass Windows

Fiberglass windows are a very popular option for home replacement windows today, since they are known for being durable and waterproof. They come with many of the benefits of wood replacement windows, but they are more affordable for homeowners who are looking to cut costs on their window replacement project. Fiberglass windows will not crack, peel, bend, or warp, and are a great option if you are looking for energy efficient replacement windows. Also, unlike aluminum frame windows, fiberglass windows do not get stuck due to heat expansion and contraction, making them more functional in the home.

fiberglass bedroom windows

Benefits of Fiberglass Windows

When choosing fiberglass windows for your window replacement project, you can expect to enjoy the following benefits.

Long lifespan

Fiberglass is one of the most durable window frame materials made today. These window frames do not have to be thick to provide strength and stability. Fiberglass frames resist weathering effectively, and the framing material lasts for up to 80 years.

Variety of color options

Fiberglass window frames can be painted at a factory location before installed, or in person by the homeowner or a window contractor. This makes it simple to get fiberglass windows in any color to fit your needs.

Resistant to heat 

Fiberglass window frames and glass panes expand and contract with heat at a similar rate. This makes them an ideal material for window construction. A vinyl window expands and contracts about seven times as much as glass, and wood windows contract about 3 times as much. These are big differences that can lead to window frame failures over time. Since fiberglass frames expand and contracts with glass, it helps protect the window from temperature changes over time.

How Much Do Fiberglass Windows Cost?

The average cost to install new fiberglass windows is $340 to $720 per window as of 2022. This includes the cost of the fiberglass window itself, plus the cost of labor and installation by a professional window contractor, which should cost between $20 and $50 per window installed.

Fiberglass Windows

Average Installation Cost $340 - $720

Cost Breakdown

  • Materials 93.8%
  • Labor 6.3%

It is important to talk to a local window professional to get a quote and recommendations based on your home’s specific needs. For instance, how many fiberglass windows do you plan to install throughout your home? Which style of window do you need in each room?

Before calling local contractors, you can use our Windows Cost Calculator tool below to get a price estimate based on your home and where you live.

Window Replacement Cost Calculator

Take Me There

Best Brands for Fiberglass Windows

Most of the top window brands offer replacement fiberglass windows, as they are one of the top choices for window installation amongst homeowners, in addition to vinyl and aluminum windows.

Choosing the right brand for your window replacement is an important part of buying new fiberglass windows. A great brand will offer you quality options when it comes to window frame materials, the best warranties, and stylish fiberglass window designs that can’t be found elsewhere.

Check out our list of the best window brands to help you find replacement fiberglass windows in your area and the cost for window replacement associated with them.

Top Window Brands

Explore the best window brands ahead of your next home windows project

Take Me There

Fiberglass Windows vs. Vinyl Windows

Fiberglass windows are arguably more sustainable than any other window frame on the market. More trees can be grown and harvested for wood window frames. However, when demand is high, it’s much easier to simply convert sand to fiberglass.

best replacement windows chart

Fiberglass is a smart buy for replacement windows because they are highly weather resistant, difficult to damage, paintable, highly energy efficient, and will not warp in heat. However, fiberglass windows look very similar to and cost more than vinyl windows.

Fiberglass windows are eco friendly and they also takes less energy to create than aluminum, wood, or vinyl window frames. These days, fiberglass is being recycled. This makes the waste from the windows less of an issue, since it can be used in cements and other applications.

fiberglass windows

Energy Efficient Fiberglass Windows

Fiberglass is an excellent insulator, which is why so many homeowners use fiberglass insulation in their homes. This same insulator quality is what makes fiberglass windows so energy-efficient. Fiberglass windows can be foam filled for even higher levels of insulation. They are known for expanding and contracting at the same rate as the glass they hold. This prevents drafts and saves you money on utility bills in the long run.

Are Fiberglass Windows Right For You?

Before deciding to move forward with a fiberglass window replacement, we recommend considering these last few points.

Look and feel

Some homeowners prefer the look and traditional charm of new wooden windows in comparison to fiberglass frames. In that case, a homeowner could install an interior wood trim on top of the fiberglass frames to combine strength and aesthetics into one with a replacement clad wood window.

Boost energy efficiency

Most fiberglass window frames are hollow inside, which reduces their energy efficiency. However, frames with foam insulation effectively increase the frame’s energy efficiency without being prohibitively expensive. You may want to discuss with your window installation contractor if you can get your fiberglass window with foam insulation.