The Pros and Cons of Fiberglass Windows

Wood, fiberglass or vinyl?

In one of the most important decisions in the window replacement process, fiberglass is often positioned as the middle-of-the-road option. It’s not quite wood but mimics the appearance. It’s a strong, durable material but isn’t as affordable as vinyl. 

There’s a lot more to choosing a window material than price or appearance. When you look at all the benefits of fiberglass windows, you’ll find it stacks up to both wood and vinyl in a number of ways.

Advantages of Fiberglass Windows

Fiberglass is a versatile material that’s used in many applications beyond window frames. You’ll find it in everything from boats and airplanes to the insulation in your own home. With so many uses, there have to be many benefits provided by the material.

1. Fiberglass is strong and durable. 

Like its name describes, fiberglass is made of glass fibers. In a very intentional process, a weft inserter weaves and knits the glass fibers into a resin injector. The glass fibers are strategically placed to ensure each lineal of material has maximum strength.

This process strengthens the otherwise fragile glass and creates an entirely new material that’s several times stronger than vinyl or wood. Because of the added strength, fiberglass frames can hold larger window panes to create eye-catching walls of glass.

The strength of fiberglass is demonstrated in its durability. Fiberglass window frames don’t damage easily, resisting the denting, scratching, warping and corroding you may see in other window materials. Pella fiberglass windows use a patented, five-layer fiberglass material to create the strongest, most durable windows in the industry.

Behind the Strength of Pella’s Proprietary Fiberglass Pella's proprietary fiberglass material is the strongest material for windows and patio doors, engineered for lasting durability. Disclosure: Pella’s proprietary fiberglass material has displayed superior strength over wood, vinyl, aluminum, wood/plastic composites, and other fiberglass materials used by leading national brands in tensile and 3-point bend tests performed in accordance with ASTM D638 and D790 testing standards.

2. Fiberglass windows are energy-efficient. 

Fiberglass windows are manufactured to withstand extreme heat and cold. The strong, durable frames are stable and rigid, so they don’t expand or contract as the weather changes. 

Since glass is an insulator, fiberglass offers the same benefits. Fiberglass windows absorb and hold heat, which helps maintain the comfort of your home in the winter and keep out the high temps in the summer.

Pella fiberglass windows have an insulating value similar to the natural insulation provided by wood windows. When combined with double- or triple-panes, fiberglass windows increase the energy efficiency of your home — and your energy savings. 

3. Fiberglass frames are low-maintenance. 

Fiberglass doesn’t warp, crack or rust. It’s difficult to damage during a construction mishap or weather event. The strength and durability of the material help it hold up.

That makes a fiberglass frame easy to maintain over the life of a window. With Pella fiberglass windows, you don’t even need to repaint them. The powder-coat factory finish is durable like the frame itself so your annual window maintenance to-do list will be short.

Disadvantages of Fiberglass Windows

Despite all of its benefits, fiberglass isn’t perfect. There are some drawbacks to choosing fiberglass windows:

1. Fiberglass windows cost more than vinyl windows. 

On average, you do pay more for the strength and durability of fiberglass. Depending on whether you're replacing one or multiple windows, the cost can add up.

On the bright side, fiberglass windows often cost less than wood windows. And once you consider the savings on maintenance, repairs and energy, fiberglass is more affordable than you think. 

2. You have fewer color options than with wood windows. 

Pella fiberglass windows should not be painted. If you’re looking for an exact color match to your home’s design, wood provides more flexibility. You can still find a complementary color scheme in one of the five solid-color or four dual-color frame options, which offers you more design versatility than with vinyl. 

That includes black fiberglass windows, a rising trend in homes of all styles that is modern yet classic. You can go with white on the interior and black on the exterior or get black window frames inside and out.

Fiberglass vs. Vinyl vs. Wood Windows

When it comes to the cost of replacing windows or the overall aesthetic of your windows, fiberglass does fall in between wood and vinyl. But there are many areas where it ranks right alongside or above its fellow materials: strength, durability, energy efficiency and maintenance. 

While you can’t go wrong with the quality craftsmanship of any of the three window materials, fiberglass might just provide the right blend of benefits at the right pricepoint for you.