Vinyl vs Fiberglass Windows

Most homeowners debate whether its best to go for fiberglass or vinyl windows, both of which are highly popular choices.

The average cost to install new windows is $350-600 per unit; depending on the quality and type of window you want.


Average Cost of 10 Replacement Windows:
Vinyl
$3520
Wood
$6895
Fiberglass
$8459

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New House Windows Cost

In this guide, we will compare vinyl and fiberglass windows based on numerous factors, such as:

– installation cost
– durability
– maintenance
– aesthetics
– energy efficiency
– fire resistance
– environmental concerns

Compare the cost of fiberglass vs vinyl replacement windows

One of the biggest distinctions between fiberglass and vinyl windows is the total cost. Since fiberglass is considered a more premium material than vinyl, it is also significantly more expensive. The difference in price between these window types can be as much as 50%.

For a basic model, fiberglass windows cost about $600-675 per unit, including installation. Prices for premium fiberglass models are $850-950 for each window installed.

For vinyl, the price for a basic window together with installation averages $350. The best double hung vinyl replacement windows cost $550 each.

Keep in mind that these estimates do not include the cost of framing the rough opening, interior trim, molding, decorative fittings. Window prices will also vary depending on unit size, type of glass and other accessories. Finally, your total costs will vary based on your geographic location, as labor rates across the US are very different.

To find out what will be the cost to replace windows in your area, get free estimates from professional local window installers.



Vinyl vs Fiberglass: which window is stronger and more durable?

types of windows

When shopping for new windows, one very important feature to consider is durability. Fiberglass replacement windows are much stronger and more durable than vinyl ones, with a high strength – to – weight ratio. In fact, fiberglass windows provide eight times greater strength than vinyl windows.

Moreover, compared to other window types, fiberglass has the highest resistance to rotting, warping, twisting and corrosion. Also, the window’s frame and sash corners will not separate or crack.

Vinyl windows have problems similar to those found in wood and aluminum window materials. All of them tend to warp, rot, crack, bow and shrink under the influence of weather conditions. Ultimately, fiberglass windows will long outlast vinyl.

Window Aesthetics

Best replacement windows

Windows make a huge impact on the overall look and feel of the space. It is important to choose a material that will maintain its appeal for many years. The advantage of windows made out of fiberglass is that they can be painted any color at any time. This means that if you ever decide to replace siding on your house, you will easily be able to repaint fiberglass windows to match it.

If you prefer the indoor look of natural wood, it is possible to order fiberglass frames with wood finishes. By contrast, vinyl windows are available in a wide range of colors and finishes that will match any architectural home styles from traditional to modern. However, it is not possible to paint vinyl windows.



Maintenance Considerations

One of the biggest benefits of fiberglass windows is that they are virtually maintenance free. You can repaint them a different color, if you choose to go for a different look. Similarly, vinyl windows will not require repainting, staining or re-finishing throughout their service life.

However, because vinyl windows expand and contract with temperature changes, this movement causes the seal between the vinyl framework and the glass to fail. This problem increases with the size of the window; the bigger the sash, the faster it fails. The worst part is that a vinyl window cannot be repaired, it needs to be replaced.

Differences In Energy Efficiency

Windows Energy Efficiency

Windows are one of the main contributors to energy loss inside a house. If you want to save on heating costs and stop wasting energy, its best to install energy efficient windows. In this respect, fiberglass windows are an ideal choice, because they boast very high efficiency. This is due to the fact that a fiberglass frame reacts to fluctuations in outdoor temperature changes in the same fashion as the glass panes. Internal stresses are reduced because all components of a fiberglass window system are contracting and expanding at the same rate.

As a result, the entire window system and weatherstripping is more airtight and resists moisture penetration. Fiberglass expands and contracts an impressive 800% less than vinyl. Moreover, fiberglass windows have a high R-value, which means they are resistant to heat loss.

Windows made out of vinyl are also considered to be an energy efficient option. They are resistant to heat loss, offering high R values, as well as provide excellent UV protection to reduce fading. However, temperature changes cause vinyl to contract and expand, increasing the chance of air leakage over time, because of this movement.

Consequently, if you choose vinyl windows it is best to specify light colors and heat-welded corners to mitigate this issue. This is especially important if you live in a region with severe temperature fluctuations, such as the Northeast, where winters are very cold, and summers are very hot.

It is important to note that whole-window U-value for a low-E argon-filled casement window carries the same 0.32 rating for both an un-insulated vinyl and an insulated fiberglass unit.

Fire Resistance

One the biggest disadvantages of vinyl windows is that they will not only burn, but will also release toxic fumes, which are highly hazardous to health. Breathing these fumes can be particularly dangerous for children. On the other hand, fiberglass windows have self-extinguishing capabilities in case of fire, and will not emit toxic fumes.

Resistance To Temperature Fluctuations

Fiberglass is particularly adept at handling extreme temperature fluctuations. It can equally withstand heat, cold and moisture, remaining strong and stable, without loss of any physical properties. By contrast, vinyl does not handle temperature fluctuations well. It becomes brittle in extreme cold, and expands and softens in extreme heat.



Environmental Concerns

If your concern is to use as much green building materials as possible, then fiberglass replacement windows are ideal. They are considered to be an environmentally friendly product, posing no threat to the environment during the manufacturing process, or to homeowners during their service life.

On the other hand, vinyl does have both environmental and health risks. In PVC production, dioxin (the most potent carcinogen known), hydrochloric acid and vinyl chloride are produced and released. Moreover, in case of a building fire or waste incineration, PVC (vinyl) releases deadly gases such as hydrogen chloride, even before it ignites. As the material burns, it leaves behind toxic dioxin waste.

To mitigate the health risks, and address the environmental concerns, the vinyl window industry reduced the amount of dioxin emissions by 70%. However, they are still not a completely risk-free window option.



Average Cost of 10 Replacement Windows:
Vinyl
$3520
Wood
$6895
Fiberglass
$8459

See costs in your areaStart Here - Enter Your Zip Code



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3 thoughts on “Vinyl vs Fiberglass Windows

  1. Ken Shum

    Its the thermal performance that attracted me more to the fiber glass energy efficient windows. These are dimensionally stable and have air cavities.Once we seal these cavities, we will be able to experience the full thermal efficiency.

    Reply
    1. Leo B Post author

      Jack,

      For the most part – PROs of vinyl are costs!
      Now if you dig a little deeper, fiberglass windows are all pretty much high end, so you cannot compare low end vinyl window to fiberglass.

      You need to take “top of the line” from your favorite manufacturer, and then compare costs.

      As for durably, both fiberglass an high end vinyl are about equally durable, and weakest point is “mechanicals”. These are your sliding mechanisms, and locks, and push-pins to swing sashes out for cleaning. They all can fail, and unless you have stainless steel parts, over time they will fail.

      Lastly, if you want a certain color – fiberglass is better in my opinion, as paint on vinyl windows may eventually start to peel off, and you will see white base.

      PS – Pacific NW doesn’t make much of a difference here.

      Hope this helps, Leo

      Reply