Fiberglass Windows

Why Choose Fiberglass Windows?

When it comes to selecting windows for your Chicago or Madison home, durability, energy efficiency, and aesthetic appeal are the three main factors that should influence your decision. Fiberglass windows excel in all these areas, making them an increasingly popular choice among homeowners and contractors alike. At NEXT Door & Window, we’re proud to offer top-quality fiberglass windows that combine strength with beauty and performance.

Fiberglass windows are engineered to withstand the harshest elements while maintaining their structural integrity for years. Made from glass fibers and resin, fiberglass windows offer superior strength-to-weight ratio, minimal expansion and contraction, and excellent insulation properties. Whether you’re building a new home or replacing your existing windows, fiberglass provides a range of benefits, making it a smart investment for any property.

Some key advantages of a fiberglass window replacement include:

Exceptional durability and strength
Superior energy efficiency
Minimal maintenance requirements
Unobstructed views
Sleek, modern appearance

Check Out Our Recent Fiberglass Window Installations

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Fiberglass Window Product Lines

NEXT Door & Window is proud to partner with Marvin Windows, giving homeowners across the Midwest access to Infinity from Marvin fiberglass windows. Constructed with Ultrex fiberglass, Infinity from Marvin windows are developed to be 8 times stronger than vinyl and easier to maintain than wood while resisting warping in harsh weather conditions.. They feature a fade-resistant acrylic finish that’s thicker than most manufacturers’, making them resistant to chipping, peeling, and denting.

Marvin Windows (available in Chicago)

Durable hardware for easy opening and closure for the life of the window
Single-sash hinge designs
Easy Wash mode

Infinity from Marvin

Clear View hinge option for maximum visibility
Ultrex® Fiberglass construction that outperforms wood and vinyl
Energy Star rated for optimal insulation and performance

Marvin Elevate (available in Chicago)

Available with standard folding handle or dual arm rotary hardware for easier cleaning
Warm wood interiors and stylish, fiberglass exterior color options offer customizable design configurations
Multi-point locking system for tight seals and protective security

Get Bigger Views With Fiberglass Windows

Because Ultrex fiberglass is so strong, Infinity window frames can be built with narrower frames. This means less material for unobstructed views. Enjoy the scenery from your home with Ultrex fiberglass windows manufactured by Infinity from Marvin.

Fiberglass Material Strength

At 8x the strength of vinyl, Ultrex is the strongest window framing material on the fiberglass window replacement market. Unlike vinyl, which can warp and shift under certain conditions, Ultrex is resistant to expanding and contracting in any climate. Furthermore, Ultrex fiberglass captures the nuanced aesthetic of wood without its required maintenance and care. This means Ultrex fiberglass windows are easy to clean without sacrificing style.

Fiberglass Energy Efficiency

While vinyl expands at a higher rate than glass, Ultrex expands at a slightly lower rate than glass. This means Infinity windows are resistant to leaks, seal failures, and stress cracks that can compromise energy efficiency and overall performance.

We submit Infinity windows and doors for independent testing and verification to achieve energy certification and labeling in programs administered by the National Fenestration Rating Council (NFRC) and ENERGY STAR®. Use the NFRC label or speak with one of our window replacement experts to compare energy performance factors across products and brands.

match your home’s décor. Choose from round-top, French casement, push-out, or in-swing designs that can be customized to meet precise size and shape requirements.

Get Started by Talking to an Expert

Want to enjoy new fiberglass windows in your home today? At NEXT Door & Window, we’ve built up a team of experienced window replacement specialists throughout the Chicagoland and Madison areas who are ready to guide you through every step of the process. Our experts are here to provide personalized advice, answer your questions, take measurements, prepare accurate quotes, and help you place your order. They’ll also assist in coordinating the installation process to ensure a smooth and hassle-free experience.

NEXT Door & Window is well-versed in fiberglass window installation. Our technicians regularly undergo training to stay updated on the latest innovations and technologies in the industry. From evaluating your current windows to helping you select the perfect NEXT fiberglass windows and overseeing proper installation, our certified experts are committed to your satisfaction.

See What Your Neighbors Are Saying

Next Door and Window

4.8

Based on 367 reviews

review us on

Bob Praljak

17:45 26 Sep 25

Excellent sales people with design choices and excellent workmanship for front double door installation. The final result looks fantastic. Highly recommended.

Ian Ostergaard

03:17 26 Sep 25

We are very happy with our new entry door.
After a brief discussion we were presented with several options to meet our criteria. Our sales representative was thorough and patient.
Communications between the purchase and installation was excellent, preempting any need to call for a status.
Installation day was efficient and well organized. The team was professional and showed a high regard for our property,
Net message a quality product installed in a quality fashion.

Ron Potempa

20:49 25 Sep 25

I had a very positive experience working with Next Door from the initial sales meeting through installation. This is my second experience working with Jason and the installation teams. The Marvin Signature windows are great and the installation team was fantastic. Their attention to detail and the care they displayed was amazing. Based on their high level of workmanship, respect for the house, and the manner in which they cleaned up after the job was completed, I would highly recommend Next Door for any window project you need done without hesitation. It was a pleasure working with the entire Next Door team.

James Kidney

20:06 25 Sep 25

We had a fairly small job replacing a front door and reframing two other doors to our courtyard. Although it took a while, the door, which os exposed on both sides, seems to be of high quality with excellent brass hinges and strong framing. We tried and failed to get Lowes, Andersen and other vendors to do the job, but for varied reasons, they refused to quote. Next Door is not cheap,but they did a great job.

David Gower

20:07 12 Sep 25

Excellent communication and high-quality work! We strongly recommend.

Ann Arellano

11:34 12 Sep 25

We liked the style of our 60-year-old windows but they and the high-maintenance outdoor wood framing needed to go! Next Door consulted with us, measured, and delivered beautiful replacements that perfectly match the look of the old windows but provide an airtight, updated ease of use (and, as we discovered due to a brief but loud construction project at our neighbor's house, a more soundproof quality that is a bonus!). Thanks to our sales contact Luke, lead installer Daniel, and support staff along the way for a great experience.

Carol

15:54 11 Sep 25

From initially stepping into Next Window showroom until after our Infinity replacement window install, our experience was amazing! Everything went so smoothly starting with our knowledgeable and helpful salesperson who had exceptional communication. During the entire process any question we had was immediately answered. The install crew was neat, friendly and helpful. The outcome resulted in a quality window with now an updated modern visual appearance. Can’t beat the extended 10 year labor warranty that Next offered as well. We are enjoying our home’s new look!

Patricia Carmichael

20:56 09 Sep 25

Below I break down each area with the good and needs improvement. I had to cut my review short because I guess I’m too wordy.

Sales: Zach Tobin was my salesman and he’s a very good salesman. He knows how to do his job and he knows the product. We purchased 12 Marvin fiberglass windows, Provia front door, and a storm door. Yes, he did his job. Products are pricey, but obviously, we agreed to it.
Process up until installation: We had a few other projects going on so we had to wait for the windows to be done. After signing the contracts you get to hear from your project manager and another individual who handles contracts. I assume it’s standard procedure. Didn’t really receive any phone calls, but rather just emails.
Installation: We had our windows installed in February. Unfortunately, that is the time one of our windows needed to go in because of remodeling the inside. I really didn’t want my house opened up to install all 11 windows when it was so cold but, unfortunately, Next stated they had to do it the same day. The installation crew (Greg and his team) arrived on time and were professional and courteous. They definitely knew what they were doing. My only complaint with this installation crew was they took out two windows and then went to lunch before reinstalling. It was about 20° outside. I mean, that is a first world problem considering I have a furnace; they were probably freezing and really hungry. Other than that, I really appreciated their expertise, thoroughness, and professionalism. Fortunately, they were weren’t able to get it to all the windows in one day so they had to come back at a later date to finish installation. They finished the installation of all the windows within 30 days of starting. Fred installed our storm door-he is FABULOUS as well.
Post Installation: I am writing this review and it is September. As stated above, the windows were installed in February. Due to quality issues, we had to have some sashes and frames replaced. In fact, the job is still not done. Still waiting on a few parts to be installed. The customer service post installation has been more than challenging. I send emails, for documentation, which go unanswered. When I speak with someone at Next, I have to explain my situation over again; kind of like they never received the emails. I stopped hearing from my project manager approximately two months ago, and to be honest, I think I only spoke with him on the phone once during this whole process. The lady I hear from the most, Kim, has a tendency to speak over you and doesn’t let you finish what you’re saying. An example of poor customer service with Kim was when we were discussing the pins that hold the window screens in place. These pins keep breaking and I requested additional ones. She requested to know how many I needed and I told her 10, which would be for five windows. She proceeded to tell me that my Warranty is up and I may have to pay for that. I questioned how my warranty is up and she said you’re no longer under warranty for customer service calls. I explained that the push pins are a part and requested the technician bring them when they finish up with the window parts. Not sure if I’m gonna be charged for those yet. However, I did comment on how poorly made the pins are that keep the window screen in place. Kim proceeded to say that’s a Marvin issue and not a Next issue. I was kind of flabbergasted and did tell her “it’s interesting Next stands behind a poor quality product”. She interrupted me to state Next has nothing to do with the pin quality ( she obviously didn’t get the correlation). I then interrupted her and said there’s no need to argue and requested her to follow up with me regarding finishing the windows. Definitely in need a better customer service.
Overview:
Contract signed in late 2024
Installation of windows in February 2025
It is now September and I’m still waiting on finishing the windows due to parts needed.
Would I do it again with Next? No (even though the installation crew was absolutely fabulous)

Vanessa Silva

21:58 08 Sep 25

We ordered windows over 6 months ago after being contacted weekly by a salesman, the process of getting them installed took very long and no one updated us on the process. Mistakes were made that further delayed the ordering process. At the time of installment we noticed the largest window was incorrect and very wrong. The salesmen then proceeded to push me to try and admit that this was a mistake made between miscommunication between my husband and I. This was hugely incorrect as my husband and I were on a three way phone call at the time of ordering. Now they’re having are ordering the correct window, it’s been over a month and barely any updates or communication on when it will be installed. NOW finance is contacting us demanding to begin payments when the project has not been completed. This is a huge headache and we have no one helping us or reaching out.

Karen Musser

14:46 08 Sep 25

From start to finish we give Next Door and Window five stars for their outstanding professional service each step of the way. We loved the finished product our new front door with sidelights. It is stunning and just how we imagined it would be when we went through the ordering process with our sales rep. Thank you Next Door and Window for your quality product and team that made it all happen.

Karyn Higgs

17:56 19 Jan 25

Very satisfied with the windows! Everyone I had contact with at Next Door was fantastic. The installers were very accommodating.

Karyn Higgs

17:56 19 Jan 25

Very satisfied with the windows! Everyone I had contact with at Next Door was fantastic. The installers were very accommodating.

James Wiley

16:06 16 Jan 25

Next Door and Window did a great job installing my window and finishing was very nice

James Wiley

16:06 16 Jan 25

Next Door and Window did a great job installing my window and finishing was very nice

Cari Beckman

01:26 14 Jan 25

Next Door and Window is my go to for all my replacement door needs. This is my 3rd project with them and I would not recommend anyone else! Great products, incredible customer service, a reputation bar none. Thank you Justin for another exceptional experience!

Cari Beckman

01:26 14 Jan 25

David Cleveland

23:24 13 Jan 25

Next Door and Window kept us updated on the progress of our order and completed the job on the day that was scheduled. They were were professional and did an outstanding job installing the windows.

David Cleveland

23:24 13 Jan 25

Next Door and Window kept us updated on the progress of our order and completed the job on the day that was scheduled. They were were professional and did an outstanding job installing the windows.

Nancy Nelson

01:08 13 Jan 25

We love our new front door with side light and storm door. Everyone was so professional and knowledgeable starting with Gary Armstrong from Sales. He came to our house and educated us on the different doors, had samples of different colors and hardware. After we made our decision he took a picture of our current front door and was able to show us exactly what our new doors would look like on our house so there was nothing left to the imagination. They offer several different options for payment. Our project manager John Nelson kept us updated along the way which was awesome because our door was confirmed to deliver earlier than expected. Installation was booked within two days of our door getting delivered at Next Door and Window. The installers Fred and Mike were right on time, professional and installation was completed perfectly. We highly recommend Next Door and Window and definitely deserve a five star rating! Thank you Next Door and Window!

Nancy Nelson

01:08 13 Jan 25

Kenneth Anderson

17:50 24 Dec 24

We needed to replace the last 5 original windows in our 120 year-old home. After much research and numerous conversations with multiple window companies, Next Door & Window of Burr Ridge was our clear choice. From initial contact at the showroom through post-installation, they have consistently been knowledgeable, patient with our questions, thorough, personable, and not aggressive. Customer service was excellent, and the employees are skilled, really nice people.
The installation went very smoothly. The windows were ready at the projected time, scheduling was flexible, and the install itself took ½ day. Cleanup was thorough, and the installers were respectful to us and our home. No stress.
The windows look beautiful, the quality is great, and we are satisfied with the value. We do realize that we need to see how the windows manage seasonal changes.
We dealt primarily with Ron, who co-owns Next Door & Window with his son. Ron is an expert in the window and door business, and the kind of salesperson you hope you get to work with. He was always striving to ensure we were completely satisfied.
It was a pleasure doing business with Next Door & Window.

Kenneth Anderson

17:50 24 Dec 24

Praveen Ravi

13:45 15 Nov 24

We had a Marvin Infinity sliding patio door installed by Next Door and Window. Sales rep Zach was good to work with and helped us arrive at a good price. Their showroom has lots of door options to browse through. Installer did a great job in removing the old door, installing the new one and cleaning up. We will go with Next Door for future projects of replacing all our windows with Marvin Infinity. Highly recommend this place for your next window/door project.

Robert Miller

14:12 16 Aug 24

We chose Next to replace our front door and side lights. The one being replaced was the original from 1999 and had all sorts of issues. We chose to go with the ProVia 460 Style Smooth Steel entry door and side lights. We opted for full glass on both in order to brighten the entryway. We also did different colors for exterior (black) and interior (white) to fit our styles. The product was built to order so there was a several week delay from purchase to installation but that was expected. Once the materials arrived they delivered it at 8am and the installer worked all day to remove the entire casement and install everything new. It is very high quality. The door is perfectly balanced and hardware aligned to spec!

We absolutely love our new door!

Robert Miller

14:12 16 Aug 24

Carolyn Bennick

17:48 19 Feb 23

Next Door and Window is definitely a 5 STAR business. Everyone at the office was extremely friendly and very helpful. Ron came out to the house in just a day or two and thoroughly explained and showed pictures of everything we needed to know about doors and storm doors, Next Door and Window also had a top-notch crew install our beautiful doors. I would highly recommend Next Door and Window!

Melissa Keating

14:26 14 Jan 23

We had two exterior doors and two storm doors installed. I am so happy with our experience with Next. They had excellent customer service from start to finish. The man who came to give us our quote did a thorough job measuring and talking to us about our options. The doors arrived sooner than expected which was a very pleasant surprise. Although it was expensive, I think it is worth it. The only negative is they told us both sets of doors would be installed on the same day with two crews, but unfortunately they sent only one man who had to come two days in a row and worked long hours to get the job done. He also moved our door stopper which left a large hole in our drywall, but didn’t tell us about the damage so now I need to figure out how to fix it.

Wendy Champion

17:00 29 Sep 22

Next Door and Window replaced an old, rotted exterior door. From the initial sales visit and estimate through installation, they were very prompt and professional. They kept me updated as to the expected installation date and the installation was done quickly and very cleanly. I am 100% satisfied with them and would highly recommend them.

Ralph Meeker

16:36 21 Jul 22

We are very pleased with our Marvin replacement windows from Next Door and Window. The windows are very attractive, interior wood stained to match our existing woodwork and exterior fiberglass with aluminum used to trim out the brick mold. Project was completed on schedule without any problems, so minimally disruptive for us. The installers did an excellent job cleaning up both inside and outside. Highly recommended.

John Knoepfle

20:14 06 Jul 22

This is our second large project with Next Door and Window. Both projects turned out even better than we expected. We had Next replace all of our doors. They look beautiful and the better seal and outstanding insulation made a huge difference in keeping the house warm in winter and cooler in summer.

Two weeks ago we had Next replace all of the windows. Again, the windows are gorgeous, the installation was flawless and looks beautiful inside and outside. It has definitely improved our curb appeal and the house just looks brighter and sunnier inside. In the current summer heat, we've also already noticed that house feels like its significantly cooler to the insulation and the windows themselves.

Everyone we've worked with at Next has been wonderful. The installation teams were courteous and very professional. They also left our home spotless. When they finished the work you couldn't even tell they were there. The management team also cares--they checked with us multiple times to make sure everything was right.

Next Door and Window is highly recommended! I've recommended them to my family, friends and neighbors.

John

Selections to Discuss with Your Expert

Our NEXT Door & Window experts are ready to guide you through the key decisions that will make your fiberglass window replacement project a success. Here are some important aspects to consider and discuss together:

Window Styles

Start by evaluating your current windows. Are you satisfied with their style and functionality, or are you looking for a change? Our experts can help you explore various window styles for your fiberglass replacement that complement your home’s architecture and meet your specific needs — from classic double-hung to sleek casement windows.

Fiberglass Options

Perhaps you’ve already chosen fiberglass for its superior qualities. There are still options to consider within this material category. Our experts can explain the specific benefits of our fiberglass offerings, including durability, energy efficiency, and aesthetic features that set them apart.

Divided Lites

Also known as grids or grilles, divided lites can add character and style to your windows. Our experts can show you a range of patterns — from traditional to contemporary — or help you design a custom look that’s uniquely yours.

Colors and Finishes

Fiberglass windows offer versatility in color options. Our experts can guide you through our curated selection of interior and exterior colors and finishes, ensuring your new windows perfectly complement your home’s style, both inside and out.

Energy Efficiency Features

Discuss the various energy-efficient options available, such as low-E glass coatings, gas fills, and multi-pane configurations, to maximize your home’s comfort and energy savings.

Hardware and Accessories

From locks and handles to screens, our experts can help you choose the right hardware and accessories to enhance both the functionality and appearance of your new fiberglass windows.

By discussing these key aspects with our NEXT Door & Window experts, you’ll be ready to make informed decisions. The result? Beautiful, efficient, and long-lasting fiberglass windows for your home.

Your neighbors trust us

Our satisfied customers say it best and keep coming back. Over 50% of our business comes from referrals and returning customers like you.

Gave us great suggestions on window replacements. We love the picture windows and other suggestions he made. He is very knowledgeable and came to our house during the installation to make sure all was going well and we were happy with the windows and installation.

Jessie R.

The installers were very skilled and knowledgeable. In my Family Room, the installer even took it upon himself to level the wood shelf under the window he was installing so the wood framing the window would be even and “look nice“ as he said. He didn’t have to put in that extra effort, but he did…he took great pride in his work.

Marianne P.

Next Door & Window worked within my schedule and timelines. They are very professional. And Scott the salesperson inspected the installers work to make sure they were doing what they were supposed to. I have nothing bad to say about them.

Larry H.

Very professional, I enjoyed visiting the showroom and being showed around the shop to see how they prepare the windows for installation, and of course meeting those who run the show!

Brett W.

FAQ's

Are fiberglass windows better than vinyl?

While both materials have their merits, fiberglass windows offer several advantages over vinyl. NEXT’s fiberglass windows are exceptionally strong, durable, and low maintenance. They resist warping, rotting, and corrosion better than vinyl. Fiberglass also has a lower expansion and contraction rate, which contributes to better energy efficiency and longevity. However, vinyl windows can be more budget-friendly initially. What you choose depends on your specific needs, long-term goals, and budget.

How long do fiberglass windows last?

Fiberglass windows are designed for exceptional longevity. While many factors can affect their lifespan, including climate and maintenance, properly installed fiberglass windows from NEXT Door & Window come with a Limited Lifetime Warranty, making them an excellent long-term investment for your home.

What is the most energy-efficient window?

Fiberglass windows excel in energy efficiency for several reasons. The material itself has natural insulating properties. Additionally, fiberglass has minimal thermal expansion and contraction, which helps maintain a tight seal and reduces the risk of air leakage.

Upgrade Your Home with New Fiberglass Windows from NEXT Door & Window

Fiberglass windows offer an unbeatable combination of strength, energy efficiency, and style. By choosing NEXT Door & Window for your fiberglass window installation, you’re making a long-term investment in your home’s value by upgrading its overall quality and durability. Our partnership with Marvin Windows ensures that you’ll receive the industry’s best products backed by expert installation and customer service.

Ready to experience the benefits of fiberglass windows in your home? Schedule your free consultation with a NEXT Door & Window expert today or stop in and see us at one of our showrooms. Our team is ready to guide you through the selection process, answer your questions, and provide a customized solution for your home.

Don’t wait to enhance your home’s comfort, efficiency, and curb appeal. The first step towards beautiful, long-lasting windows is just a click away!