Compare Aluminum vs. Fiberglass Windows


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Aluminum vs. Fiberglass Windows

In the battle between aluminum vs. fiberglass windows, here are four key places to compare and contrast these frame materials - window prices, style and appearance, durability and strength and, finally, energy efficiency.

Window Prices

Both aluminum and fiberglass are more expensive than vinyl, but less than wood frames. Basically, each of these materials is a step up from a vinyl window, but not as pricy as a wood clad window. Many wood clad windows actually use aluminum or fiberglass on the outside for protection (such as the Marvin Intergity), but we are talking a full aluminum or full fiberglass window in this example. Expect an aluminum or fiberglass frame to cost $600 to $650 fully installed for a standard casement window.

Style And Appearance

Aluminum windows have a style and look all their own. They are sleek and modern, with a kind of austere look to them. The frame is often slimmer than aluminum or vinyl and therefore offers lots of glass area. Fiberglass windows tend to look similar to vinyl frames, although generally a bit thinner. Most consumers will choice the fiberglass because it looks more like a normal window, whereas aluminum is often reserved for a modern looking home. Aluminum windows really shouldn't be used in cold climates due to their poor energy efficiency.

Durability & Strength

Aluminum is the strongest of all window frames and some manufacturers such as Milgard offer a commercially rated aluminum frame that is very strong indeed. The frame is very durable and can withstand very hot temperatures and is therefore a good choice for very warm locations, although as we will detail below it is not a good option for cold climates. Fiberglass is a strong material, just not nearly as strong as aluminum. However, for residential home fiberglass windows will provide more than adequate strength and durability.

Energy Efficiency

Aluminum windows are not good in terms of energy efficiency, definitely the bottom of the barrel in this category. Nearly all aluminum windows made today are thermally broken and offer much better efficiency than aluminum of the past, but they still do not provide great performance numbers. Fiberglass is at the top of the list in terms of energy efficiency and is offers slightly better numbers than comparably priced vinyl windows.

Bottom Line

Aluminum windows are a good option for warm climates, but should not be used in cold climates. Fiberglass windows are a step up from vinyl in terms of price and performance and are solid performers in most climates. Obviously, the manufacturer and model you purchase will be huge factors in how they perform and last over time. See Pella window prices on their fiberglass Impervia Series.

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