Vinyl vs. Fiberglass Windows: What’s Best for Your Colorado Home?

Should I Pick Vinyl or Fiberglass Replacement Windows?

When it’s time to replace your windows, the question we hear most from homeowners is: “Should I go with vinyl or fiberglass?”

At Gravina’s Window Center of Littleton®, we’ve been helping Colorado families make smart, long-lasting window decisions since 1973. Let’s break it down.

How to Choose: Fiberglass or Vinyl?

Every window material has trade-offs, but when you live in Colorado’s unpredictable climate, performance matters more than ever. You want windows that look great, hold up over time, and protect your home from extreme heat, cold, wind, and snow.

Appearance and Curb Appeal

Fiberglass windows mimic the classic look of real wood and can be painted to match your trim. Because they’re more stable, the frames can be narrower, giving you larger views and more daylight.

Vinyl windows are available in a range of colors but cannot be painted later. The frames are thicker, and over time, they may fade or warp in direct sunlight.

Winner for modern design flexibility: Fiberglass

Cost & Long-Term Value

Vinyl windows are often cheaper upfront. Their thermoplastic material is easier to mass-produce and install.

Fiberglass windows cost 15–30% more, but here’s the tradeoff: they outlast vinyl by decades and typically offer a better return on investment due to superior performance and longevity.

Pro Tip: Vinyl windows can be purchased at big-box stores. Fiberglass windows, especially Infinity from Marvin® - are only available through certified dealers like us, with professional installation included.

Durability in Colorado Weather

Colorado’s climate puts every window to the test.

Vinyl windows resist rust and won’t rot, but the material expands and contracts with temperature swings, causing seal failures and warping over time.

Fiberglass windows, especially Ultrex® from Infinity by Marvin, are engineered to resist warping, cracking, and seal failure even in sub-zero temps or blazing sun. They’re reinforced with pultruded fiberglass, making them 8x stronger than vinyl.

Winner for high-altitude durability: Fiberglass

Energy Efficiency

Both materials outperform outdated wood or aluminum windows. But only fiberglass is dimensionally stable—meaning it doesn’t flex with temperature changes. That makes fiberglass the better insulator.

Less air leakage = lower energy bills →

Resale Value & ROI

Buyers notice quality. Fiberglass windows improve resale appeal thanks to their lifespan, energy savings, and high-end look.

According to remodeling cost/value reports, fiberglass consistently ranks higher than vinyl for ROI in resale.

Long-term winner: Fiberglass

So… Should You Choose Fiberglass?

If you’re remodeling your forever home or want maximum value with minimal maintenance—fiberglass is the clear choice. That’s why we exclusively install Infinity from Marvin® fiberglass windows at Gravina’s Window Center of Littleton.

They’re engineered for Colorado, backed by a Lifetime Labor Warranty, and installed by our factory-certified team.

Free Estimate from Colorado’s Window Experts

• 52+ years of experience
• Family-owned and operated
• Colorado’s oldest Infinity dealer
• No-pressure consultations

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