How do fiberglass vs vinyl windows match up against one another? Let’s examine these two window materials on price, strength, energy efficiency and overall look.
Bottom Line: Vinyl Windows are certainly the more popular of the two materials, accounting for some 70% of all new windows sold today. Fiberglass is the stronger and significantly more expensive of the two options.
Vinyl Overall Rating: 8.5 — Fiberglass Overall Rating: 8.0
Questions on fiberglass vs vinyl windows – send us an email and ask away!
Vinyl Windows vs Fiberglass On Cost
Vinyl window prices are the least expensive of the five main window material options (wood, composite, aluminum, fiberglass and vinyl). The price range you can expect might run $400 to $1400 per window fully installed and this is with retrofit installation. If the window requires full frame installation, you can expect to add another $250 per window to the overall cost. This is obviously a big price range.
As a rule of thumb, fiberglass windows prices will be 35% more expensive than vinyl, although there aren’t all that many low end fiberglass windows. My overall price range is $1400 to $2000 per window fully installed and this is with retrofit installation. Just as with my vinyl example above, add $250 for new construction installation.
Vinyl Windows Price Range: $400 to $1400 each
Fiberglass Windows Price Range: $1400 to $2000 each
Winner On Pricing: Vinyl
Compare Window Prices
Simonton Window Cost: $750 installed (vinyl)
Window Universe Cost: $1725 installed (fiberglass)
Harvey Window Cost: $750 installed (vinyl)
Okna Window Cost: $900 installed (vinyl)
Marvin Window Cost: $1925 installed (fiberglass)
Compare On Strength
Fiberglass is the stronger of the two materials. In some sense, the strength question is moot because windows are not load bearing. Therefore, they really only have to support their own weight, which is not a difficult task. Cheap vinyl windows might have a problem in this regard. Good and great vinyl windows will not. However, fiberglass windows are still the stronger of the two.
Winner On Strength: Fiberglass
Fiberglass vs Vinyl Windows On Energy Efficiency
The worst vinyl windows will have much worse energy efficiency over The best vinyl windows will win out over the top fiberglass windows. More specifically however, this is a tough one to judge on because this is going to vary window to window. The most energy efficient window is the Okna 800 series. The least efficient option might be the Silverline V1 window.
Storm Series Rating: 7.5
Comfort Series Rating: 7.0
Rhino Series Rating: 8.5
Winner On Energy Efficiency: Toss Up
Compare On Overall Look
250 Series Rating: 7.0 — Encompass Series Rating: 6.0
Impervia Window Series Rating: 6.5 — Lifestyles Series Rating: 8.5
Hurricane Shield Rating: 8.0 — Designer-Series Rating: 9.5
Winner On Overall Look: Fiberglass
Fiberglass vs Vinyl Windows Q And A
Explore our question answer section from homeowners who have grappled with this question over the years. We’re happy to answer your questions if you want to drop us a line.
Bill – Site Editor
Ideal Majestic vs. Provia Endure
Dane, the Ideal Majestic windows quoted comes w double strength glass, while the PE windows quoted came with single strength glass. Everything else being equal, the IM windows are, on average, $50 more per window. The prices would be equal if the PE windows were upgraded to double strength glass. Having 25 windows to replace, should I pay the extra $50/ window and if so, should I go with IM or the Endure Provia Windows. Lastly, is DSG overkill and SSG fine for my southeastern PA home on a quiet street for the next 20 years? What do you think of fiberglass vs vinyl windows and how they compare to one another?
Dave – Homeowner – from 2025
[Site Editor’s Answer]
Dave, I think the double strength glass is worth $50 per window. If my timeline were 20 plus years, I think it makes sense to pay for the upgrade. Ideal Majestic vs. Provia Endure – I just had this question from someone else and I basically said I can’t say which is better, they are both terrific. I would judge it on the company doing the install (assuming they are different) and/or which one I thought looked better, which is subjective. Either way, you are sitting pretty!
In terms of vinyl vs fiberglass, I think your selections are good and there is no need to bump up to fiberglass, which will run you like 40% more in cost over what you have here. I do like fiberglass, but it is a tough material based on the overall price point.
Dane – Site Editor – from 2025
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