How much thought do you give your windows? You certainly have given your windows some amount of thought, because they do play an essential role in your home’s overall function. They let in light, which reduces the need to burn power on artificial illumination. They allow fresh air in when the weather’s fair. They also provide a, well, window to the outside world so you can see what’s happening.
Your windows also play an important role in your home’s exterior aesthetics. This is why there are so many varieties of pane and glass styles from which to choose.

Your home says a lot about who you are. You surround yourself in what you find pleasing. This not only reveals your personal style but also will make a lasting impression on friends, family, colleagues, neighbors, and everyone who drives by your home. Your curb appeal is also important because it impacts the resale value of the homes around you. This can directly impact your relationship with others in your community (for better or for worse).

How your windows look is important, but the aesthetic aspect isn’t all there is to it. Windows have to stand up to some real challenges. They have to provide a reliable, secure seal against the outside world, and it’s a unique challenge for glass. Have you ever noticed, in winter, that no matter how toasty your home is, those window panes are really cold? And the reverse in the summer, as well? There’s a reason for this, and it’s called thermal conduction.

Modern, quality windows are designed to decrease this heat exchange in a couple of ways. For one, the glass itself is designed to be less conductive, though this can never be perfect due to transparency letting energy transfer. The other measure, which further reduces this is the dual-pane approach (sometimes triple) used in most window designs. There is argon or krypton gas suspended between these panes of glass, which are harmless, inert gases that don’t exchange heat very well.

Windows also have to be very strong, withstanding impacts in storms and other forms of severe weather. You probably had at least a basic understanding of this, but what about the framing on the windows? Does it matter?

The short answer is yes, and there are a few different materials, including metal, wood, vinyl, and fiberglass. Today, we’re going to look at the ups and downs of vinyl and fiberglass with hopes to point you in the direction of which choice suits you best.

If metal or wood appeals to you more for one reason or another, we’re not saying that vinyl or fiberglass are the only viable choices. However, wood and metal do tend to be a lot more expensive these days and aren’t always as readily available as these synthetic materials. Before we compare them, though, permit us a small caveat.

No Single Truth

Neither of these is the end-all choice for anyone. They both have their benefits and their downsides, and it all comes down to what benefits outweigh what disadvantages on a case-by-case level.
We want to show what trade-offs each have alongside the unique benefits of each one. That said, let’s start with vinyl, which is a longer-established material for windows.


Vinyl is, believe it or not, a type of plastic. There are various grades of vinyl, mostly made from ethylene (a crude oil derivation) and chloride (a salt component). The chemical name for vinyl is polyvinyl chloride, or PVC (yes, that PVC), though it’s generally just referred to as vinyl.

When you think of vinyl in general, you probably think of flooring, seat covers, or old-fashioned records. This makes it seem like an awfully flimsy material to use for something like windows. However, when you consider that very strong products like PVC piping are also vinyl, it starts to make a bit more sense.


  • Cost-Effective: Vinyl is a lot easier to manufacture than fiberglass, which is quite a process itself. This makes it a lot less expensive in the long run (about a thousand dollars cheaper per 10 48” windows).
  • Low Maintenance: Vinyl doesn’t fade in sunlight, and you don’t need to paint it. It’s recommended that you don’t paint most vinyl, as it doesn’t bond well with most paints (except for vinyl-based ones). This makes it less of a hassle as it ages.• Longevity: You can expect up to 30 years from this material, which is pretty impressive.
  • Availability: This is much more readily available than fiberglass.


  • Warps in Heat: Vinyl outgases, which does weaken the bonds. This outgassing means that it can warp in extreme heat, which is a downside to vinyl siding as well.
  • Thermal Expansion: This is the real problem. With temperature fluctuations, vinyl can expand and contract, which can warp the frame and even shatter the glass.
  • Poor Seal: When it does warp, the seal can be compromised.
  • Poor Insulation: Vinyl doesn’t insulate very well, hence PVC pipes being wrapped in cold climates to prevent bursting.


Fiberglass is a newer technology than vinyl, though not by that much. It’s a woven fiber material with glass embedded in it for luster and rigidity. Fiberglass is used in a wide range of products, from pool liners, signage, automotive bodies, siding and of course, window frames.


  • Thinner and Tougher: Fiberglass provides a thinner frame, which allows for more glass and a more understated frame. It also doesn’t warp or contract like vinyl.
  • Better Insulation: It insulates much better against noise and heat exchange, as well as providing a superior seal.
  • Better Looking: It has a superior luster and can take on more styles and colors.
  • Longevity: Expect up to 50 years out of fiberglass.


  • Very Costly: Expect a considerable increase in cost for this material.
  • Hard to Install: It’s hard to install fiberglass.
  • Requires Painting: Occasionally, you will have to paint this material, and it does fade in sunlight.
  • Availability: This is far less readily available.

Which is right for you? It depends on which of these drawbacks is more severe, and which benefits mean the most to you. To learn more, fill out our contact form today!