ProVia The Professional Way

Bay & Bow WINDOWS IN ST. LOUIS

Looking to upgrade your home with beautiful, energy-saving bay windows in St. Louis? STL Windows & Doors is your trusted local window contractor, specializing in high-performance ProVia bay and bow windows. Our custom installations offer exceptional style, comfort, and value.

The difference between bay and bow windows lies in their structure. A bay window includes three sections: a large center window flanked by two smaller angled ones. In contrast, a bow window has four or more equal-sized windows that curve outward to form an arch.

Both styles can feature fixed, double-hung, or casement window types. Contact us today for a free estimate.

Bay and Bow windows in a St. Louis residential home living room

Bay & Bow Window Styles

At STL Windows and Doors, we proudly offer ProVia bay and bow windows, along with a wide range of customization options, to elevate your home. Bay and bow windows are not their own style, like double hung windows or casement windows.

They utilize various window types, constructed both decoratively and functionally. Choose from a variety of colors, decorative or stained glass, privacy or tinted glass, and interior grid styles to match your aesthetic.

Endure

ProVia Endure Double Hung Window
Stunning Energy Efficiency

Aeris

ProVia Endure Double Hung Window
Pre-finished wood interior & vinyl exterior

Aspect

ProVia Endure Double Hung Window
Energy Savings Simplified

DOWNLOAD WINDOW BROCHURES

Bay & Bow WINDOW COLORS & FINISHES

Here’s a sample of our bay and bow window color and finish options. Whether you prefer a painted or stained look, we offer a wide range of styles to complement your home—inside and out. Click through the sections below to explore interior woodgrains, exterior colors, and hardware finishes designed to match any aesthetic.

Oak Wood Species

Cherry Wood Species

Maple Wood Species

FOR INSPIRATION

WINDOW GALLERY

Aeris Bay Window Front of Home in St Louis

PROVIA Windows OFFER STUNNING ENERGY EFFICIENCY

ProVia is known throughout the industry for delivering exceptional quality, energy efficiency, and extensive customization options.

Their Endure double-hung vinyl windows are an ideal choice for St. Louis homeowners, offering advanced energy-saving technology that ensures long-term performance and reliability.

When you want the best, choose the window that Remodeling Magazine named the #1 vinyl window for quality—ProVia Endure.

Provia, recognized as 2024’s Most Efficient Energy Star® certified for windows, promises high energy efficiency by meeting strict EPA standards, reducing homeowners’ heating and cooling costs.

Energy Star Most Efficient 2024 Award

WHAT CUSTOMERS SAY

Posted on Google Google
Jeff Gordon profile picture
Jeff Gordon
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Peyton and Max installed 21 new windows and a new front door. They were a pleasure to work with, especially since we had other home improvement projects going at the same time. They did meticulous work and answered all of our questions.
Posted on Google Google
Mike Kelly profile picture
Mike Kelly
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
I had a great experience with STL Windows and Doors. They we're booked up initially, but they still were able to setup an appointment and put me on the schedule. This company has great prompt customer service, fair pricing, and great professionalism. I would highly recommend their service.
Posted on Google Google
Anne Croy profile picture
Anne Croy
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Excellent service with initial sale and installation!! High quality product.
Posted on Google Google
Vivian Saied profile picture
Vivian Saied
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
I used Stl windows and doors to replace half of the windows in my house and a sliding door. The whole process was excellent. From talking with Dan, the sale manager to the installers (Tony and his crew ) to Scheduling with Chris at the office. First of all, Chris was able to up my schedule date a week early upon my request. I'm sure he squeezed me in his tight schedule. I was very thankful. Tony and his crew were very professional, yet friendly and considerate. They were prompt on time the 3 days they came and very efficient. They took down my window treatments and put them back up again exactly the way they were. They moved furniture and put back. They took the time to explain how the windows opened from top to bottom as the windows had many options that my old windows didn't have. I would use them again and would definitely recommend them to my family and friends
Posted on Google Google
Elizabeth Purcell profile picture
Elizabeth Purcell
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Worth the wait! Price was insanely different from other bids for a single window replacement. Paid cash for a slightly better rate. Originally was going to need to wait 8 months for replacement but I got lucky & they fit me in at the 4 month marker since they had a cancellation. Customer service from Kaleb & Tony was outstanding. Both were very personable & made me feel confident that the job was being done well. Great warranty! Glad to check this off my list:)
Posted on Google Google
Aaron Fox profile picture
Aaron Fox
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
STL Windows and Doors did an excellent job with our window replacement project. We live in an older home (over 100 years old) and we know there are going to be issues related to its age. The STL Windows and Doors team worked extremely hard with us to replace one of our bathroom windows that had begun to show signs of water damage. After the initial window replacement project was finished, we did communicate with their team about concerns we had with the original window frame that remained. Chelsea worked with us and a team (Tony and Caleb) came to our house within a week and replaced the frame as well. Their prices were reasonable and they had an array of choices. Overall, we highly recommend them for any window-related project you may have!
Posted on Google Google
Jake Bloomer profile picture
Jake Bloomer
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Experience was great, STL W+D replaced our old rear door and transom with a new eight-foot unit. It’s great to have this huge pane of glass looking out over the back yard. Installers were great and clean and shimmied the door in without removing our old casing and messing with the plaster. They know what they are doing!
Posted on Google Google
Randall H profile picture
Randall H
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
The removal of the old window and the installation of the new window went more smoothly than I would have expected. Peyton and Max were knowledgeable, professional, and completed the installation beautifully and efficiently. Both of them did a great job with making in the new window secure, sealed, and attractive.
Posted on Google Google
T Baker profile picture
T Baker
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Premium products and service at a more affordable price. Fantastic experience at every step of the process. Had some hail and tornado damage. Jared (sales) was friendly and knowledgeable about the industry. Did not hard sell, but instead provided a balanced and very detailed explanation of STL's products and services vs competitors, which felt trustworthy. Dan (owner) came out to measure the windows. My spouse said he was friendly and answered her questions. We got an unexpected scheduling break and installed much sooner than the expected wait. The installers, Peyton and Max, were friendly, efficient, and conscientious of our home. Their finish work (sealing and caulking) is better than the original for the house. They took the time to demonstrate all the features of the new windows and how to care for them. We all noticed a defect in the glazing inside one of the window sashes, which they immediately reported to the owner who, in turn, called me immediately about the manufacturer's quick replacement. Provia warrantees the vinyl, glass, hardware and screen of the window for life and this guarantee is transferable once to a new home owner. The installation has a 10-year guarantee. Also, STL has another business for window cleaning and screen replacement, which we're going to check out.
Posted on Google Google
Jessica Klemp profile picture
Jessica Klemp
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Great company to work with! We needed four hopper windows replaced on our garage/basement and STL Windows and Doors provided the best service and most competitive pricing. The work was done quickly and professionally, and everyone we met from the company was friendly. We would recommend calling them for your window needs!

Why Homeowners Love Bay and Bow Windows

Bay Bow Window Interior

Bay and bow windows aren’t just beautiful—they create a striking focal point, offer a sweeping panoramic view of the outdoors, and bring lasting value to your home. With their timeless design and versatility, they’ve become a favorite upgrade among St. Louis homeowners seeking more light, space, and style. If you’re considering a curved window design and want to explore your options further, check out our guide, A Bow Windows Guide For Your Home.

At STL Windows and Doors, we use only the highest-quality products on the market—like ProVia windows—and rely on our skilled, experienced teams to bring your vision to life. From design consultation to expert installation, we’re here to make your dream windows a reality.

A well-designed bay window turns heads. Its angular design projects outward, giving your home a more prominent, upscale look.

Bow windows, with their sweeping curve, are perfect for adding a timeless elegance to living rooms and dining spaces.

Like garden windows, bay and bow windows extend outward from the house to increase natural light and add functionality to your space. Both window styles flood your room with daylight while creating additional square footage inside.

Think cozy seating nooks, plant displays, or even extra storage. These custom bay window upgrades are especially valued in compact St. Louis homes where space and sunlight are at a premium.

Our ProVia energy-efficient windows feature triple-pane, low-E glass with argon gas insulation. You’ll enjoy more daylight without the extra heat during the summer and less heat loss during winter—perfect for our Midwestern climate.

Whether you choose bay, bow, casement windows, or double-hung options, energy efficiency remains a top priority.

Bay windows offer an excellent return on investment. Their visual appeal and functional space make your property more attractive to buyers. They’re a top pick in St. Louis home improvement projects.

COMPARE Bay vs bow windows

Use the comparison table below to see how bay and bow windows differ in shape, function, and design. This quick side-by-side guide will help you decide which style best suits your space, lighting needs, and budget.

Feature

Bay Windows

Bow Window by Provia

Bow Windows

Bay Window by Provia

Shape

Angular (typically three panels)

Curved (typically four or more panels)

Number of Panels

Usually 3 (center fixed, side panels operable)

4 to 6 equal-sized panels

Projection

Extends farther out from the wall

Extends out in a gentle curve

Appearance

More modern or angular look

Softer, rounded, classic appearance

View

Offers a wider, more focused view

Provides a panoramic, wraparound view

Natural Light

Allows more light than flat windows, less than a bow window

Allows maximum natural light

Interior Space

Creates additional space (suitable for seating)

Creates slightly more interior space than bay

Customization

Limited to 3-panel configuration

Highly customizable in size and number of panels

Cost

Generally more affordable

Typically more expensive due to complexity and size

Installation Complexity

Easier and faster to install

More complex and labor-intensive

WHY CHOOSE STL WINDOWS & DOORS?

We’re your trusted source in St Louis and pride ourselves on being the go-to experts for high-quality Provia replacement window installation. We try to embody a commitment to excellence that homeowners trust. Our dedicated team brings unparalleled skill, ensuring every project meets our stringent standards for installation quality.

While the windows offer excellent ventilation, we strive to create an excellent experience from beginning to end. High ratings and minimal complaints about Provia’s windows show that customer satisfaction is at the core of everything we do. Homeowners can rely on our professional services and feel secure in their choice — because ensuring your peace of mind is part of what we promise.

STL Windows and Doors Team Installing Windows

Upgrading to stylish casement windows can completely transform your space, whether you’re building new or renovating. These windows offer wide-open outdoor views and dependable indoor security. When installed by the best window installers, you get more than energy efficiency—you get precise craftsmanship, seamless operation, and a flawless finish.

At STL Windows and Doors, our team takes pride in being among the best window installers in the St. Louis area. We use advanced tools and accurate measurements to ensure every window fits perfectly and performs as it should.

We proudly serve the St. Louis metro and surrounding communities, delivering expert installation on window styles that enhance your home’s curb appeal and bring the outdoors in.

As a ProVia Platinum Dealer and Certified Installer, we’re committed to quality you can trust.

We're a ProVia Platinum Dealer and Certified Installer

These windows are built to last, featuring advanced weather stripping and multi-point locking systems that enhance security and comfort. Their durable vinyl frames resist warping, chipping, and peeling, helping maintain a clean, polished look that adds to your home’s curb appeal.

With ProVia, customization and quality go hand in hand. Each window is made to order, tailored to match your personal style and your home’s architectural character.

Whether you’re aiming for a sleek modern aesthetic or replicating classic charm with decorative muntins, these windows integrate effortlessly into any new build or renovation—while elevating your home’s exterior appeal.

10-Year Workmanship Warranty

As a trusted window company serving the St. Louis Metro, we make quality installation our top priority—every casement window project reflects our commitment to excellence. Your satisfaction with your new windows is our promise.

We back our craftsmanship with a 10-year workmanship warranty, ensuring long-term performance and peace of mind for your home.

TOP Bay & Bow WINDOW FAQ

Do you have questions about bay and bow windows? You’re not alone! Below are some of the most frequently asked questions we receive from homeowners. If you don’t see your question here, please don’t hesitate to reach out, as our team is here to provide expert guidance and top-quality window installation throughout the Greater St. Louis area.

Absolutely! Adding a window seat or built-in storage beneath a bay window is a popular way to enhance both style and function. It’s a smart use of space that not only adds charm but also expands your living space—perfect for reading nooks, extra storage, or a cozy spot to relax and enjoy the view.

Yes, in most cases, a standard window can be replaced with a bay or bow window—especially when installed by experienced professionals. This upgrade not only transforms the look of your home but also enhances air flow and provides expansive outdoor views. At STL Windows and Doors, we assess your existing structure to ensure proper support and deliver a seamless installation that maximizes both form and function.

Yes—depending on your configuration, you can choose operable window types (like casement or double-hung) for the side panels. The center panels are often fixed for an unobstructed view but can also be operable if desired.

When installed properly and built with energy-efficient features like triple-pane, low-E glass and argon gas insulation (as in ProVia’s Endure series), bay and bow windows can perform just as well as traditional flat windows.

GRAB A DEAL AND FREE ESTIMATE BELOW

Take the first step towards a new look with a bay or bow window.