20 Best Window Companies in Alton, IL (2025 Reviews)
Are you looking to replace your windows? Our guide to the best window installation companies can help you choose the right one for you.
We analyzed all the top-rated window companies in Alton and selected the best 20 based on:
Customer reviews
Window installation expertise
Popularity with home-owners like you
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Why you can trust EcoWatch
Whether you're updating for aesthetics or have damaged windows, windows play a key role in conserving your home's energy. If your house has old or damaged windows, your HVAC system could be working extra hard to heat or cool your home. This means higher power bills.
Replacement windows improve your home’s insulation, not only making you more comfortable during extreme temperatures, but also saving you money and helping the environment.
Efficient windows are especially important in Alton, where the temperature varies throughout the year. According to Energy Star, switching to energy-efficient windows can save the average homeowner up to $313 a year.
Best Availability
Renewal by Andersen
- Great Industry Reputation
- Award-winning Company
- Member of US Green Building Council
- Manufactures products in-house
Best Energy-Efficient Features
Champion
- Many years of experience
- Low prices relative to competitors
- Limetime warranty
Power Home
- Uses eco-friendly materials
- Well-trained, certified installers
- Lifetime or lengthy warranty
Best Window Installation & Replacement Companies in Alton
The EcoWatch team assessed dozens of installers across the country to find the top window replacement companies for our readers. We assessed the providers based on their energy-efficient offerings, local experience, price, coverage area, customer service and more.

Window World
EnergyStar Partner
Large serice area
Low prices relative to competitors
Great industry reputation
Lifetime warranty
Quality of service will depend on your area
Window World provides windows expertise in Alton. Window World has over 27 years of experience in the industry, and it currently provides services to 200 locations nationwide.
You may want to consider going with Window World if you're looking for a installer that is certified by the Environmental Protection Agency (EPA) and Energy Star and supports charities like St. Jude Children’s Research Hospital.
Energy Efficiency of Window World WindowsWindow World caters to eco-conscious consumers by providing energy-efficient window offerings. Its high-performance Low-E (low-emissivity) coatings and argon gas insulation offer exceptional efficiency and performance for any home.
How much does Window World cost in Alton?Although pricing information is not available on Window World’s website, it's known for offering some of the most affordable window installations around. If you’d like to know for sure, you can ask for a quote on the company’s website.

Renewal by Andersen
Great industry reputation
Award-winning company
Member of US Green Building Council
Manufactures products in-house
No lifetime warranty
More expensive than competition
Renewal by Andersen provides the best availability in Alton. Andersen has over 27 years of experience in the industry, and it currently provides services to nearly every state except Mississippi and West Virginia.
You may want to consider going with Andersen if you're looking for a installer that uses in-home estimates and advanced digital tools to help you plan and visualize your project before getting started.
Energy Efficiency of Renewal by Andersen WindowsRenewal by Andersen caters to eco-conscious consumers by providing energy-efficient window offerings. A handful of windows manufactured by the Andersen corporation were awarded Energy Star’s “Most Efficient” in 2021, and Andersen was named Energy Star’s Partner of the Year in 2019.
How much does Renewal by Andersen cost in Alton?Although pricing information is not available on Andersen’s website, based on customer feedback, you can expect to pay anywhere between $750 to $1,250 per window for an installation with Andersen. If you’d like to know for sure, you can ask for a quote on the company’s website.

Window Nation
Award-winning company
Manufactures products in-house
Custom designs
Wide variety of products and services
Installation not covered by warranty
Limited service area
Window Nation provides the best residential windows in Alton. Window Nation has over 16 years of experience in the industry, and it currently provides services to residents within 75 miles of its showrooms, which are in 13 states.
You may want to consider going with Window Nation if you're looking for a installer that gives customers the opportunity to view products and to speak to a representative in person in its showrooms.
Energy Efficiency of Window Nation WindowsWindow Nation caters to eco-conscious consumers by providing energy-efficient window offerings. Each product has windowpanes coated with a Low-E (low emissivity) glaze that prevents damaging UV rays from heating your home. Plus, the spaces between double- and triple-pane windows are filled with argon gas that’s been proven to improve home insulation.
How much does Window Nation cost in Alton?Although pricing information is not available on Window Nation’s website, based on customer feedback, you can expect to pay between $300 and $525 per window installed, making it a more affordable option compared to competitors. If you’d like to know for sure, you can ask for a quote on the company’s website.
We’ve recommended companies with good reputations, but note that some national companies have independently owned locations in Alton, so the quality of service may differ depending on your local crew. We have tried to be unbiased and transparent by mentioning pros and cons for each company reviewed.
More Window Companies in Alton
Renewal by Andersen
Maryland Heights, MOGood Customer Service
Price Transparency
Free assessment
Timely Service
Educational Website
Services Offered
Skylights
Glass Doors
Bay Windows
Double-Hung
Window Replacement/Installation
Champion Replacement Windows of St. Louis
Fenton, MOGood Customer Service
Free assessment
Price Transparency
Services Offered
Double-Hung
Window Replacement/Installation
Glass Doors
Bay Windows
Window Nation
Overland, MOGood Customer Service
Price Transparency
Free assessment
Educational Website
Services Offered
Energy-Efficient Options
Bay Windows
Double-Hung
Custom Window Designs
Glass Doors
Vinyl Frames
Window Replacement/Installation
Gateway Door and Contracting
St Charles, MOFree assessment
Educational Website
Good Customer Service
Price Transparency
Services Offered
Window Replacement/Installation
Windows Doors & More LLC
St Charles, MOFree assessment
Educational Website
Good Customer Service
Services Offered
Energy-Efficient Options
Window Replacement/Installation
Chaney Windows And Doors
Maryland Heights, MOPrice Transparency
Free assessment
Good Customer Service
Educational Website
Services Offered
Wood Frames
Bay Windows
Glass Doors
Window Replacement/Installation
Vinyl Frames
Energy-Efficient Options
Colonial Construction
St. Louis, MOEducational Website
Good Customer Service
Services Offered
Window Replacement/Installation
Home Comfort Exteriors
St Peters, MOFree assessment
Good Customer Service
Price Transparency
Services Offered
Energy-Efficient Options
Window Replacement/Installation
Building Envelope Experts
Fenton, MOPrice Transparency
Good Customer Service
Educational Website
Timely Service
Free assessment
Services Offered
Vinyl Frames
Bay Windows
Energy-Efficient Options
Window Replacement/Installation
Custom Window Designs
Double-Hung
Glass Doors
Butler Home Improvement
Collinsville, ILFree assessment
Price Transparency
Educational Website
Services Offered
Window Replacement/Installation
STL Windows and Doors
Earth City, MOPrice Transparency
Educational Website
Good Customer Service
Timely Service
Free assessment
Services Offered
Window Replacement/Installation
Double-Hung
Bay Windows
Glass Doors
Cardinal Contractors
St. Louis, MOGood Customer Service
Price Transparency
Free assessment
Services Offered
Window Replacement/Installation
Quality Installation
Swansea, ILFree assessment
Good Customer Service
Services Offered
Glass Doors
Window Replacement/Installation
Gateway General Contractors
O'Fallon, MOGood Customer Service
Free assessment
Educational Website
Price Transparency
Services Offered
Window Replacement/Installation
Lyons Glass Company
Alton, ILPrice Transparency
Good Customer Service
Free assessment
Services Offered
Glass Repair
Window Replacement/Installation
Mirrors
Glass Showers
Glass Doors
Tempered Glass
Glass Doctor of St. Charles, MO
St Charles, MOEducational Website
Good Customer Service
Price Transparency
Services Offered
Glass Showers
Mirrors
Glass Doors
Energy-Efficient Options
Tempered Glass
Custom Glass
Window Replacement/Installation
Glass Repair
Window Repair
L&D Wilson's Siding & Roofing Inc
Lebanon, ILTimely Service
Free assessment
Price Transparency
Good Customer Service
Services Offered
Window Repair
Double-Hung
Window Replacement/Installation
Energy-Efficient Options
Jones Home Improvements
Cottleville, MOGood Customer Service
Free assessment
Price Transparency
Services Offered
Window Replacement/Installation
Mills Window & Door Showroom
Fenton, MOPrice Transparency
Free assessment
Good Customer Service
Services Offered
Glass Doors
Window Replacement/Installation
Jacob Sunrooms, Exteriors & Baths
Fenton, MOEducational Website
Good Customer Service
Free assessment
Price Transparency
Services Offered
Window Replacement/Installation
Vinyl Frames
Glass Showers
Fiberglass Frames
Energy-Efficient Options
Calculate how much you can expect to pay for window installation and replacement in Alton, IL using our customized window cost calculator.
Estimates will vary based on window dimensions and other unique factors to your home. Getting in touch with a local window installer is the best way to get an accurate cost estimate for your home.
How Installing Energy-Efficient Windows in Alton Saves You Money
Upgrading to energy-efficient windows can help improve the comfort of your home and help you save on energy bills. Here are more ways upgrading your windows could benefit you:
- Save on power bills: Switching to energy-efficient windows reduces your energy bills by about 12% since you use less energy.
- Protect your investment: Upgrading and repairing your windows is an important part of maintaining your property and its value, particularly if you have an older home.
- Protect your valuables: Many Energy Star certified windows have low-emissivity coatings, which not only insulate your home better, but also filter out harmful UV rays, preventing your furniture, carpet and other valuables from fading.
- Reduce your carbon footprint: Because energy-efficient windows improve the insulation in your house, you can cut your indirect greenhouse gas emissions by about 12%, according to Energy Star.
Estimated Cost of Window Replacement in Alton
Each window installer provides varying services and has different price points depending on a few factors.
How Much Do New Windows Cost?
The average cost to replace one window is about $600 but can range anywhere from $200 to $1,200. But costs vary considerably depending on the size of your home, complexity of the installation, your location and the quality of the company you choose. Many window installers also offer door installations, which will add extra costs to your project.
With windows, efficiency is one of the most important factors for many homeowners. Windows with higher efficiency may cost more off the bat, but by increasing the efficiency of your home — especially during the summer and winter — they can give you many years of energy savings. According to Energy Star, buying certified energy-efficient windows can save Alton homeowners $313+ per year after replacing single-pane windows.
Requesting free quotes from several companies is the best way to find out which one will work best for your budget.
What Services do Window Installers Offer?
There are generally two types of window installation services: full-frame and pocket installations.
A full-frame installation replaces the entire window, including the sill, frame, trim and the window panes. As this type of installation is more involved, it will cost more than a pocket installation. Pocket installations (or retrofits) involve replacing a window within the existing frame, which makes pocket installations more simple and affordable. But, if the frame has any damage or rot, you will most likely need a full-frame installation instead.
Your window installation company should be able to help you choose which type of installation you need.
Best Availability
Renewal by Andersen
- Great Industry Reputation
- Award-winning Company
- Member of US Green Building Council
- Manufactures products in-house
Best Energy-Efficient Features
Champion
- Many years of experience
- Low prices relative to competitors
- Limetime warranty
Power Home
- Uses eco-friendly materials
- Well-trained, certified installers
- Lifetime or lengthy warranty
How We Choose the Best Window Installers in Alton
EcoWatch differs from most reviewers because we evaluate these companies through a sustainability lens. We’ve reviewed the best window replacement companies in Alton primarily based on energy efficiency, as it’s the most sustainable option and the best one for homeowners. Energy-efficient windows have been shown to lower power bills by hundreds of dollars. Along with energy efficiency, our rating methodology considers the following factors:
Service Area
This one is self-explanatory, but we’ve chosen to highlight window installation companies that serve the Alton area so you can find the best window installation company near you.
Work Quality
When picking new windows, the quality and range of services often plays just as important of a role in overall efficiency and performance as the brand of window you opt for. We do rate window installers higher if they offer high-quality products, but we also consider workmanship as reflected in customer feedback.
Customer Reviews
Customer feedback is another very important review factor. If most customers don’t have good things to say about their experience with a certain company, it won’t be featured on EcoWatch.
Cost
This one is a give-and-take: as with most services, cheap window installation companies may not provide the most quality service. On the other hand, we want to make sure we’re highlighting companies that provide a spectrum of price and financing options so they’re accessible to most homeowners.
Warranty
Protecting your investment in new windows is important to many homeowners. That’s why window installation companies that provide lengthy warranties for products, parts and labor rank higher with EcoWatch.
Years of Experience
Last but not least, we like to see companies that have been in the industry for quite some time. Window installation companies that have more years of experience are going to earn higher rankings by our standards. We like to see at least ten years of experience.
Alton, IL Window Replacement FAQs
How much should window installation cost?
The national average cost of installing a single window is around $600 but can range between $200 and $1,200, based on several factors. The price is often influenced by the type and material of the window, the location of your property and the size of the window. Also, remember that energy-efficient windows may cost more upfront but can save you hundreds of dollars a year in energy bills.
Which kind of window should I get?
Generally, double-pane windows are more efficient than single-pane windows and windows that don’t open will be more efficient than windows that do. To be sure you’re getting the most energy-efficient windows, look for models with the blue Energy Star certification attached to them — this means they’re certified energy-efficient by the U.S. Department of Energy.
Can you replace your own windows?
Even though it is possible to install your own windows, doing so is time-consuming and requires a lot of handiness. Hiring a professional can help guarantee that the installation is done properly and that you can avoid spending the time and effort of doing it yourself.
Should I replace my windows all at the same time?
If your windows are greater than 20 years old, you probably need to replace all of them. At that point, they are usually less efficient, draftier and/or more damaged than new windows. Replacing your windows all at once will involve less paperwork and less time.
How long does window installation take?
Because the average installation time of a window is 30 minutes, about 16 windows can be installed during an 8-hour work day.