Fiberglass and vinyl are among the most popular window frame materials today. In this guide, we’ll explain the advantages and disadvantages of both vinyl and fiberglass windows so you can decide on the perfect fit for your new build or home improvement project.
What to Know About Vinyl Windows
Extruded vinyl windows are made from polyvinyl chloride (PVC), a type of durable plastic.
Advantages of vinyl: Vinyl windows are low-maintenance, especially compared to wood windows, and they’re one of the most affordable window options available. Vinyl is also a good insulator, performing better in extreme temperatures than aluminum windows.
Disadvantage of vinyl: The main downside of vinyl is that it is subject to warping with temperature fluctuations, which can cause seal failure and shorten the window’s lifespan.
Extruded Vinyl vs. Vinyl-Clad
The term “vinyl windows” typically refers to windows with frames made entirely from extruded vinyl. Another option is vinyl-clad windows, which are wood windows wrapped in PVC. This keeps many of the advantages of the PVC but reduces some of the disadvantages, like warping, since the wood interior adds temperature stability.
What to Know About Fiberglass Windows
Fiberglass is made from glass fibers bound with a resin, which are then pulled through a heated die to form the desired shape. The result is a highly durable but lightweight material.
Advantages of fiberglass: Fiberglass is much stronger than vinyl and has a longer lifespan. It’s also the most energy-efficient window frame material with low thermal conductivity and resistance to warping.
Disadvantage of fiberglass: Fiberglass is a premium material that comes at a higher upfront cost than extruded vinyl windows.
Fiberglass vs. Vinyl Windows
Both types of window materials are popular for a reason! Fiberglass and vinyl are good insulators, low maintenance, and come in a variety of color options. Ultimately, the best choice for a home’s windows comes down to budget and performance needs. Vinyl is the more cost-effective option, while fiberglass offers better energy efficiency and durability as well as more design options.
Energy Efficiency
Vinyl and fiberglass windows are both energy efficient options and can incorporate double-pane or triple-pane glass and low-e coatings for improved performance. However, fiberglass is the most energy efficient choice overall.
Fiberglass expands and contracts at about the same rate as glass, preventing issues with warping and leaking. It also has very low thermal conductivity — meaning it’s a better insulator than vinyl. (Fiberglass is even an excellent noise insulator, making it a better choice for areas with traffic noise!)
Vinyl, while still a good insulator, more easily transfers differences in temperature between indoors and out. It’s also less rigid than fiberglass and prone to warping in extreme temperatures.
Durability and Lifespan
PVC is a thermoplastic material, meaning vinyl products are created by melting the plastic and letting it harden again. Because of this, extruded vinyl window frames can warp when exposed to very high temperatures, causing air leaks.
Like any product, vinyl windows vary in quality, and the cheapest window grades have been known to fail after as little as ten years. High-quality extruded vinyl windows may last up to 20 or 30 years. Fiberglass window frames are exceptionally durable, engineered to last around 50 years.
Appearance
Vinyl windows have wider frames, and the seams may be visible since the corners are welded together. Because vinyl is less rigid than fiberglass, it can’t support very large expanses of glass. For this reason vinyl windows are only available in more standard sizes and styles.
Fiberglass windows have more customization options than vinyl because the material is stronger. For example, fiberglass windows have thinner frames that let in more natural light and can support large panes of glass — making them a popular choice for modern homes with large window walls. Fiberglass is also a better choice for black windows, since a dark color on vinyl windows contributes to heat absorption.
Price
Fiberglass windows are a more premium option and cost more than extruded vinyl windows. If a homeowner needs low-maintenance windows and doesn’t live in a region with severe temperature swings, high-quality vinyl windows can be a great budget-friendly choice. But for optimal energy performance and long-term durability, fiberglass windows are worth the investment!
Will vinyl windows decrease a home’s value? Does fiberglass increase resale value?
A common concern is whether a particular window material will increase (or decrease) a home’s value. As a general rule, replacing old windows with new, energy efficient materials is a good idea — whether vinyl or fiberglass. The specific effect this has on the home’s value depends on a lot of other factors.
In some situations, all the buyer will notice is that the windows are new and made from materials that help insulate the home well. However, fiberglass windows are a more premium option and buying from a trusted name like Marvin may make a difference when selling a higher-end home.
Why We Recommend Marvin’s Fiberglass Windows
Modern Kitchen featuring Marvin Essential Direct Glaze Windows
Marvin is a trusted window brand and a leading manufacturer of fiberglass windows. Marvin’s proprietary Ultrex® fiberglass material is eight times stronger than vinyl. Homeowners can also choose Marvin windows protected by high-density fiberglass exteriors — Marvin’s strongest fiberglass material yet.
If fiberglass windows are the right choice for your project, we highly recommend Marvin’s premium-quality fiberglass windows. The Marvin brand consistently innovates designs that meet the highest standards for both performance and craftsmanship.
Ring’s End is proud to be the top Marvin windows dealer in the Northeast, supplying contractors and homeowners with new windows and replacement windows they can trust. If you have any questions about window materials or Marvin windows, please contact our window team using our online chat, by phone, or by texting (203)-PRO-HELP. We’d love to discuss your project!