Windows come in five materials: aluminum, vinyl, wood, fiberglass, and composite blends. They all vary in price point, energy efficiency, longevity, appearance, and other factors that are likely on your list when comparing options. Fiberglass and vinyl are two popular materials that can both provide great performance, but you should be aware of some key differences before making an investment. Below, we go over each material’s advantages, which is better for your goals, and how to find a quality version of each.
Our Take: Are Fiberglass or Vinyl Windows Better?
We’ll let you know upfront that fiberglass is the more expensive choice, but it offers more bang for your buck. It’s more energy-efficient, durable, and long-lasting than vinyl. Whether or not it’s worth investing in, though, depends on a few factors, such as your climate and how long you plan to live in your home.
If you decide to go with fiberglass, we recommend Marvin and Pella. If you decide vinyl is the better choice, we suggest looking into our reviews of Castle, Window World, or Champion.
We recommend fiberglass if you:
- Live in a cold climate and want maximum energy performance
- Are in a storm-prone area, as fiberglass holds up better to wind and impact
- Care about curb appeal and aesthetic customizations
We recommend vinyl if you:
- Are on a tight budget
- Want to install the windows yourself
- Live in a mild climate
Pros and Cons
Fiberglass performs better across the board, but if its price tag is out of reach for you, don’t worry. Today’s best window companies make plenty of high-quality vinyl options that still lower your energy bills and last for many years. Truthfully, the differences in the factors below aren’t astronomical. However, it may be worth investing in the edge fiberglass provides if your location’s weather calls for a more heavy-duty window.
If you plan to be in your home for the long haul, you’re more likely to see the return on a fiberglass investment in the form of lower electric bills over time, more comfort year-round, and less wear and tear on your HVAC system.
Fiberglass
Pros
- More attractive and easy to customize
- Better energy performance
- More durable and long-lasting
Cons
- Most expensive material option
- Must be installed by a professional (an extra fee)
Vinyl
Pros
- One of the most budget-friendly materials
- Easy to install on your own if you’re DIY savvy
- Low-maintenance
Cons
- Not as durable or long-lasting
- Less energy-efficient
Comparing Fiberglass and Vinyl Windows Side-by-Side
Here’s a quick look at which may be better for you before we get into the finer details.
| Characteristic | Fiberglass | Vinyl |
|---|---|---|
| Cost* | $800–$1,800 | $600–$1,500 |
| Lifespan | 50+ years | 20–40 years |
| Energy efficiency | High | Moderate to high |
| Maintenance | Low | Low |
| Appearance | Sleek, paintable, customizable, can be textured to resemble wood | More basic, fewer color options, clunkier look |
| Eco-friendliness | More eco-friendly | Less eco-friendly |
| Installation | Requires a professional | Can be installed by a skilled DIYer |
*Costs are an average of responses from our 2024 survey of 1,500 homeowners.
Cost
As the superior performer, fiberglass is typically the most expensive window material. Vinyl is one of the cheapest materials, second only to aluminum. The price tag on your new windows comes down to the brand, special features (such as impact resistance, tinted glass, or noise blocking), window style and size, and customization options. The most basic fiberglass window from one brand could be comparable in cost to the most elevated vinyl option from another.
Because of those factors, price isn’t always straightforward. In early 2024, we surveyed 1,500 homeowners who had recently purchased replacement windows and learned that fiberglass windows cost an average of $1,286, while vinyl windows cost an average of $1,132. That may not seem like much if you’re just buying one or two windows, but if you’re upgrading your entire house, it can be a difference of a few thousand dollars.
| Number of Windows | Fiberglass Cost | Vinyl Cost |
|---|---|---|
| 5 | $6,430 | $5,660 |
| 10 | $12,860 | $11,320 |
| 15 | $19,290 | $16,980 |
| 20 | $25,720 | $22,640 |
Lifespan
A window’s lifespan is how many years its features are expected to hold up and do the job they’re designed to do, such as any glass coatings or insulation components. How long it can last varies based on the window’s construction and craftsmanship, but the warranty is a good indicator.
Most window warranties cover the frame material and 20 years or more. Some actually cover the material for as long as you own the home the window was installed in, meaning the manufacturer expects it to stand the test of time.
Fiberglass is known for having a longer life pan than vinyl. Its makeup is stronger and more weather-resistant. It’s not as prone to warping and cracking as vinyl is, so your window’s seal is less likely to break. In U.S. climates, it can last up to 50 years or longer before it starts underperforming.
Vinyl has a worthwhile lifespan of 20–40 years but typically gives way to the elements before fiberglass frames. It’s more vulnerable to extreme temperatures, causing its appearance and energy features to break down more quickly.
Energy Efficiency
Fiberglass was created specifically for insulation. It’s made from glass fibers embedded in resin. It doesn’t expand and contract much when exposed to fluctuating temperatures outside, so it’s better at stabilizing your home’s temperature inside. That thermal stability makes it a better choice for climates with extreme temperatures, such as northern areas or desert areas that have hot days but cool nights.
Vinyl is made from polyvinyl chloride (PVC), which is a synthetic plastic polymer. It’s durable but more vulnerable to heat and cold. This tendency to expand and contract with the temperature makes it harder for it to stabilize your home’s temperature compared to fiberglass. For those in more moderate climates, vinyl should still provide the energy performance you need. A good way to check this is to look for a window’s Energy Star label. This label tells you that it’s been tested and certified by Energy Star, plus which climate it’s recommended for.
Maintenance
Both fiberglass and vinyl are low-maintenance window materials, far more low-maintenance than wood windows, for example. If they accumulate any buildup, you can easily scrub it away with some warm water and a brush.
Be aware, however, that painted fiberglass may fade and eventually need to be repainted. Also, because of vinyl’s tendency to expand and contract, you may need to replace the caulking every few years.
Appearance
Just because vinyl windows are cheaper doesn’t mean they look cheap. Most people aren’t going to spot the difference in vinyl and fiberglass’s appearance at a glance. However, there are some differences that may make fiberglass more appealing to some homeowners.
For starters, you can paint fiberglass. That means you can get it in more colors, whereas vinyl typically comes in five to 10 standard neutral tones. Fiberglass is more customizable to your preferences.
Because it’s easier to manipulate the facade of fiberglass, you can also texturize it. This is beneficial if you want to mimic the look of wood without dealing with the upkeep of wood windows.
Lastly, vinyl frames are often bulkier than fiberglass. Vinyl is a more flexible material, which means you have to build a thicker frame to uphold its structural integrity. This isn’t a major difference compared to fiberglass, but it results in a little less natural light and outdoor view.
Eco-Friendliness
Fiberglass is the more environmentally sound material—ideal for eco-conscious homeowners. This is partly because it’s more energy-efficient, so you’re using less energy to cool and heat your home. Plus, because fiberglass is largely made of glass, it can be recycled.
The way each material is manufactured also makes an impact. Producing vinyl releases harmful chemicals into the environment. If your home catches fire, those chemicals are leached into the air once again. Fiberglass doesn’t produce harmful byproducts.
Installation
Because vinyl is more flexible, it’s easier to install. It’s also more forgiving of slightly off measurements. Because of this, an experienced DIYer can likely install vinyl windows and avoid paying an extra $100–$200 per window for professional installation. That’s why it’s common to see premade vinyl windows in home improvement stores, whereas fiberglass windows must come straight from the manufacturer. However, if you don’t have the required tools, you’ll need to weigh whether investing in the necessary equipment to do the job is still cheaper than hiring a pro.
Fiberglass is a rigid material, so everything must be exact. It’s also heavier and requires more reinforcement. For these reasons, you have to hire a licensed installer or use the manufacturer’s in-house installation team.
Regardless of which material you go with, always check your warranty to see if there are any terms stating that using an unlicensed installer will void your warranty coverage.
FAQs About Fiberglass and Vinyl Windows
Why are fiberglass windows more expensive than vinyl?
Fiberglass windows are generally more expensive than vinyl windows because fiberglass is more energy-efficient, durable, and long-lasting. The price difference is also because fiberglass has a more complex manufacturing process.
Do fiberglass windows increase home value?
Installing new windows increases your home’s value, but this isn’t material-specific. Having new fiberglass windows, which are known as the most energy-efficient and long-lasting material, can sweeten the deal for a buyer, but the material isn’t likely to impact your home’s bottom line. Fiberglass windows do tend to come with a lifetime warranty that’s transferable to the next homeowner, so this can also be attractive to buyers.
Are fiberglass windows good in cold weather?
Yes, fiberglass windows are a good investment if you live in a cold climate. Fiberglass is highly energy-efficient. It’s also a stable material, so it’s less likely to expand and contract in fluctuating temperatures the way other materials do. That allows it to better insulate and keep your home comfortable.
What windows are better than vinyl?
Fiberglass has better energy performance and durability than vinyl windows. Wood windows have great curb appeal and suit many homeowners’ aesthetic preferences. For those in moderate climates who care more about budget than window appearance, vinyl is still a quality window material.
