Window & Sliding Patio Door Installation Services

At Home Comfort Exteriors, we proudly install Alliance windows and sliding patio doors. With more than 30 years of experience, we've helped thousands of homeowners improve the comfort, appearance, and energy efficiency of their homes with quality products that are built to last. We offer a variety of window styles to fit your home's needs, including double hung, picture, slider, and casement windows, along with sliding patio doors. Alliance products are designed with durability, performance, and everyday living in mind, giving homeowners a great combination of beauty, strength, and energy efficiency. Whether you're replacing a single window or updating your entire home, we're happy to help you explore your options and find the right fit for your budget. Contact us today for a free, no-pressure estimate.

House With Windows — St. Peters, MO — Home Comfort Exteriors

Lifetime Window Warranty

The Assurance Plus® Limited Lifetime Warranty applies to manufacturer defects and/or component failures:

  • Covers labor and materials for a lifetime
  • Is transferable to a second owner for up to 10 years
  • Features a standard 25-year accidental glass breakage warranty for double hung and slider windows
  • It is the best warranty in the business. Remember, the only reason our warranty can be this good is the quality of its product.

Why Homeowners Choose Us

We have installed thousands of windows and sliding patio doors over the years, and we take pride in making the process as simple and stress-free as possible. Our installers are all highly trained, experienced, and committed to treating your home with the same care they would their own.  Every installation includes the removal of your old windows or doors, professional installation of the new ones, insulation, caulking, and a thorough clean-up once the job is completed. We also remove and reinstall blinds when needed.


All of our windows and sliding patio doors come standard with Low-E coated glass, argon gas-filled double panes, and foam-filled vinyl frames for improved energy efficiency and comfort. These features help keep your home cooler in the summer, warmer in the winter, and more comfortable year-round. We believe in offering high-quality products, professional installation, and honest pricing, all without the high-pressure sales tactics. If you would like to learn more, we're always happy to provide you with a free, no-pressure estimate and answer any questions you may have.

Windows &

Sliding Patio Doors FAQs

  • Are your windows custom-sized or stock?

    All of our windows are custom made to fit your home's exact window openings. We take detailed measurements before ordering to ensure a proper fit, helping your windows look great and perform their best for years to come.

  • What type of warranty is offered for your windows and sliding patio doors?

    We install Alliance windows and sliding patio doors. They come with a lifetime warranty on seal failures and the moving parts that keep your windows working properly. They also include a 25-year accidental glass breakage warranty on their double hung and slider windows, which is a really nice added layer of peace of mind. 


    In addition to the manufacturer's warranty, we here at Home Comfort Exteriors stand behind our work with a 25-year workmanship warranty. We take pride in doing the job right and we want you to feel confident knowing your investment is protected for years to come!

  • Are there color options other than white?

    Yes, Alliance offers several color options available beyond white. Keep in mind that upgraded colors do come with an additional cost.

  • Are the windows single or double paned?

    All of our windows are double-paned. That means they have two layers of glass with an insulating space in between, which helps with energy efficiency and overall comfort in your home.

  • What time of the year is the best to replace my windows or sliding patio door?

    We install windows and sliding patio doors year-round and take special care during the cold of winter or heat of the summer. When it is extremely hot or cold outside, we always have the new window or sliding patio door ready to be installed as soon as the old one is removed to try and maintain the temperature in your home.

  • How do I know if I need to replace my windows or sliding patio door?

    If your windows or sliding patio door are original to the home, especially builder-grade products, they’re often ready for replacement after around 20 years. 


    You will usually start to notice the signs over time: drafts coming through, difficulty opening or closing them, or issues like failed seals that cause fogging between the glass. When those things start showing up, it’s typically a good indication that it is time to consider replacing them.

  • Will replacement windows increase the value of my home?

    Yes—replacement windows can definitely be a selling point for potential buyers. New, energy-efficient windows are often seen as a big plus because they improve comfort, reduce energy costs, and take one more project off a buyer’s list.


    All of the windows we install are Energy Star rated, so they’re designed to perform well in both efficiency and everyday comfort. While every home is different, upgrading your windows can be a great way to add appeal when it comes time to list your home.

  • What do Low E, Argon Gas, U-Factor, R-Factor, and Warm Edge Spacer mean?

    These are all different features and ratings that describe how energy-efficient a window is and how well it keeps your home comfortable. 

    • Low E is a special coating on the glass that helps reflect heat and UV rays, so your home stays cooler in the summer and warmer in the winter. 
    • Argon gas is an invisible gas sealed between the panes of glass that adds extra insulation. 
    • The U-Factor and R-Factor are simply ways to measure how well a window performs; one tells you how much heat can escape while the other shows how well it resists heat loss. 
    • The Warm Edge Spacer is the piece between the glass panes that helps reduce heat loss around the edges and can also help with condensation. 

  • Do you repair window screens or broken windows?

    We don’t offer repair services; we focus on full replacements. In most cases, replacing the window is the better long-term solution anyway, since it addresses the full performance of the unit, not just the visible issue.

Contact Us At 636-928-8900