20 Best Window Companies in St. Charles, MO (2025 Reviews)

How Installing Energy-Efficient Windows in St. Charles Saves You Money

Switching to energy-efficient windows can improve the comfort of your home and help you save on power bills. Here are more details about how switching out your windows could help you:

• Protect your investment: Upgrading your windows is an important part of maintaining your property and its real estate value, especially if your home is on the older side.
• Reduce your carbon footprint: Reducing how much energy you use also lowers your indirect greenhouse gas emissions. You could reduce it by 763 pounds per year on average.
• Save money on energy bills: Once you switch to energy-efficient windows, you can see a reduction in your bills by about 12% since you’ll require less energy to heat or cool your house.
• Protect your valuables from fading: The low-emissivity coatings on many energy-efficient windows filter out harmful UV rays, preventing your furniture, carpet and other valuables from fading.

Estimated Cost of Window Replacement in St. Charles

Windows come in different shapes and sizes, so costs and services will differ tremendously. Here are the average costs and the primary services that you can find from window installation companies.

How Much Do New Windows Cost?

The average cost to install a single window is about $600 but can range from $200 to $1,200. These numbers vary depending on specific characteristics of your installation, such as size, type, material, number of windows, the location of your home and more.

Bear in mind that energy-efficient windows may have a higher price, but Energy Star estimates the upgrade will save you between $101 and $583 per year when you install single-pane windows and between $27 and $197 per year when you replace double-pane, clear glass windows. Your exact savings will vary based on your local climate, energy rates and individual home characteristics.

The cost of your window installation will also vary based on the type of window material you choose for the frames. Wood windows are typically the most expensive, though it depends on whether they are solid wood or clad with aluminum or vinyl. Fiberglass windows also tend to be a bit more expensive than vinyl, but they are more efficient.

What Services do Window Installers Offer?

The first question to ask yourself when considering a window replacement is: Do you want a full-frame installation or a pocket installation?

Full-frame installations require replacing the full window — the sill, frame, trim and all. These are most common when you want a new style for your windows or when it has a great amount of rot or deterioration. Full-frame installations are more time-consuming and will increase overall costs. A pocket installation entails replacing a window within the existing frame. So, instead of removing the whole window and rebuilding it, the contractor will just slide the replacement window (also called a retrofit or insert window) into the frame.

Your window installation company will be able to help you choose what’s best for your needs. In St. Charles, the decision will mostly be based on how old your windows are and if there’s any damage. Wood can decay if not maintained properly over the years, so it’s a good idea to have a professional check your frames and window sills.

How We Choose the Best Window Installers in St. Charles

In our search to find the most reliable, eco-friendly window installers in St. Charles, the EcoWatch team landed on the above companies as the top window installation companies in the city. Along with energy efficiency, we analyzed each installer and assigned rankings based on the following methodology:

Service Area

Since this is a guide for St. Charles, we gave more points to companies that serve the city. There are certainly other reputable providers that didn’t make our list because of the low odds that they would serve the average homeowner in St. Charles.

Work Quality

When picking new windows, the quality and breadth of services often plays just as important of a role in insulation and performance as the brand of window you choose. 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 super important review factor. If the majority of customers don’t have nice things to say about their experience with a certain installer, it won’t be featured on EcoWatch.

Cost

This one is a give-and-take: similar to other services, cheap window companies may not provide the highest quality service. Still, we want to make sure we’re highlighting companies that provide a range of price and financing options so they’re accessible to most homeowners.

Warranty

Protecting your investment in new windows is important. For that reason, window installation companies that have 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 a good track record in the industry. Window installers that have more years of experience earn higher rankings by our standards. We like to see at least ten years of experience.