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

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

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

• Reduce your carbon footprint: Decreasing the amount of energy you use also lowers your carbon emissions. You could reduce it by 763 pounds per year on average.
• Save on energy bills: According to the Department of Energy, heat gained or lost through windows makes up around 25-30% of residential energy use. Replacing your windows with energy-efficient models can help lower how much energy is used in your home, therefore saving you about 12% more on your bills.
• Protect your valuables: The low-emissivity coatings on many energy-efficient windows help prevent damage from the sun's UV rays to your floors, carpets and furniture.
• Protect your investment: When your home is on the older side, your windows could also be outdated or drafty. Upgrading your windows is an important part of maintaining your property and its value.

Estimated Cost of Window Replacement in St. Louis

When researching window installation, each company provides different services and prices. Let’s go over some average costs and services.

How Much Do New Windows Cost?

According to our research, the typical cost of replacing a single window is about $600. However, window installation costs can range from $200 to $1,200 per window. But costs vary remarkably depending on the size of your home, complexity of the installation, your location and the quality of the company you choose. Many window companies also provide door installations, which carry a higher price tag.

Whether or not you pick energy-efficient windows is another factor that will influence the cost. These will typically cost more than other windows, but on the other hand, you can save about $374 a year on your energy bills in St. Louis.

Getting free quotes from multiple installers is the best way to figure out which one is right for you.

What Services do Window Installers Offer?

Generally, there are two types of window installation services companies provide: full-frame and pocket installations.

Full-frame installations are usually done when you want to change the style of your windows or your window has significant rot or deterioration. With this service, your installers will replace the total window, including the trim, sill and frame. A pocket installation involves installing a new window without replacing the frame. This means instead of taking out the whole unit and reinstalling it, the installer will just put the replacement window (also called a retrofit or insert window) into the frame.

If you’re still trying to decide which kind of installation you need, you can ask your installer and get their recommendation. The decision mostly depends on how old the frames are and if there’s any damage present.

How We Choose the Best Window Installers in St. Louis

EcoWatch reviews differ from most reviews since we assess these companies through a sustainability lens. Along with energy efficiency, we reviewed several window installers in St. Louis and ranked them using the following methodology:

Service Area

Because this is a guide for St. Louis, we paid more attention to companies that cover the city. There are certainly reputable providers that didn’t make the cut because of the low odds that they would serve the average homeowner in St. Louis.

Work Quality

We’re willing to bet that you’re looking for professionals who do a great job installing windows. We’ve vetted each installer included in our guide to make sure its technicians are well-qualified and that the company has gotten a lot of positive customer feedback to vouch for its service.

Customer Reviews

Customer feedback is another very important review factor. If most customers don’t have nice feedback about their service from a certain company, you won’t see it featured on EcoWatch.

Cost

This one is a give-and-take: as with most services, cheap window companies won’t always provide the highest quality service. On the other hand, we want to ensure we’re highlighting companies that offer a wide range of price and financing options so they’re accessible to most homeowners.

Warranty

As discussed previously, windows are a substantial investment, so you’ll want to be certain that investment is well protected. Window installation companies that give you lengthy warranties for products, parts and installation (aka workmanship) rank higher with EcoWatch.

Years of Experience

Due to St. Louis’s climate, homeowners will want to mitigate rot, low efficiency and water damage. We factored in local experience to reflect the ability of St. Louis window companies to prepare homes for these issues. If a company has less than 10 years of experience, it loses points in this category.