Bay Window vs. Bow Window

sliding bay window

Also called “Projection Windows,” bay and bow windows have a curved shape. Instead of sitting flush against a wall, they project outwards. This feature allows them to have a good view of the outdoors. They are staples in new constructions and for the right reasons. Both the options make for stunning additions to any home boosting the curb appeal.

Though they look similar, they have their subtle differences and are unique in their way. However, the differences are so subtle that house owners have difficulty choosing the one that best fits their aesthetic.

This article takes you through the bay and bow windows. Our experts have put together a detailed walkthrough of their differences and their subtle nuances.

What is a Bow Window?

bow window

Also called compass windows, bow windows are comprised of four or more panes. All the window panels are of identical shape and size, thus creating a subtle curve. They work better in corners and exterior walls with a surface area of 80 inches or more. They are generally referred to by the number of windows, such as four-lite bow, five-lite bow, and so on. Adaptable and flexible, bows can also be wrapped around the corners of the house. They form an appealing turret shape on the exterior with an inviting nook inside.

What Era is Bow Windows?

Bow windows trace their roots in the eighteenth century in the United Kingdom, especially in the country estates. They give a clear view of the landscape beyond, filling the room with more sunlight. Moreover, they can also be seen in the late colonial/early republic period homes in the United States.

What is a Bay Window?

Rather than a smooth circular structure of the bow windows, bay windows feature more angular lines. They generally consist of three panels, of which two on the sides are operable. And the one in the center is inoperable, acting as a picture window. The operable windows feature either casement windows or double-hung window types.

Bay windows are often seen in contemporary- and transitional-style homes. However, due to the versatile nature of the windows, they look as good in traditional designs such as victorian- and cottage-style homes.

Are Bay Windows Worth It?

Bay windows are specialty windows that are way ahead in terms of architecture and style. The aesthetic value alone increases the curb appeal of your home. Bay windows also increase the square footage, thereby increasing the market value. In addition, it can brighten the room for an extended period of time with better ventilation due to the two operable windows.

However, they require careful installation to ensure that its installed right. If not, they are bound to develop structural issues. So, all in all, considering everything, bay windows are worth every penny.

Can Bay Windows be Opened?

Bay windows consist of three windows, of which you can open two of them. However, you cannot open the center window. The windows that can be opened are either casement windows or double-hung style.

What is a Box Bay Window?

A box bay window is a familiar sight in many houses across the UK. They are generally shaped like a rectangular box, hence the name. They are a common type of bay windows used mainly in the UK with flat sides, a flat front, and a roof. A box bay window with slanted sides is also called the canted window.

What is the Difference Between Bay and Bow Windows?

Bay windows and bow windows both have similar architectural features that protrude from the wall. And, they have more than one panel tailored together to form a single unit. However, both have a few key distinctions that make them unique. The main difference is architecture. One form of window is angled, while the other has a curved structure.

Here are a few key differences between the two window options.


A bay window generally consists of three windows with a picture window in the center. And on the sides, it has smaller windows. A bow window, on the other hand, comprises four to six windows and curves outside. Each window is of a similar size, thereby creating a gentle curve. This is especially appropriate for a Victorian house but can also be a great addition to a modern house. Because of the size and shape of these windows, you may have to order custom treatments increasing the total cost.

Increased Space

Of the two window styles, bay windows are those that add square footage. You can use the additional interior space for storage or as a window seat. However, they take up quite a bit of outdoor space. This can become a problem if your home is pretty close to the street or sidewalk.

Bow windows generally have a small ledge but add no actual area. So if you don’t have much open space, this is the way to go. But they take more than a bit of wall space, while bow windows never take that much floor space.

Design Aesthetics

Bay windows look nice in modern homes as their angles are shaped. However, they have been around for hundreds of years and can be seen in colonial homes. Bow windows make up some of the newer designs. But, bays are more versatile and are ideal for modern, colonial, and traditional homes. On the other hand, if you live in a historic Victorian house or an upscale home, bow windows will fit right in.


Ventilation is not an option with bow windows. The opening mechanisms can interfere with the architecture. But, bay windows offer better ventilation because they can contain more venting options. They have one large picture window center and two narrow sides down either side. Picture windows will not open since they are formed from a fixed glass pane. However, the side windows are operable. They can either be casement, double-hung, or single hung.


bay and bow window

Installing both windows is quite challenging even for a professional. This is because they are much more complicated than a standard window. Due to its larger size and weight, the bow window is more difficult to install. However, both types may present challenges for a DIY installation. The existing window opening will need to be enlarged and expanded to fit the current frame. It’s best to get window installers to do this renovation project.

Resale Value

With a proper installation, both bow and bay windows can increase the resale value of the house. A beautiful and appealing glass window featuring sparkling glass will attract buyers. It has also been proven to increase light. Moreover, it also reduces clutter while ensuring good ventilation inside and outside.

Natural light

Bay and bow windows allow lots of natural light than flat windows. However, bow windows are perfect for homes that require abundant light. Natural light is said to improve health by preventing seasonal affective syndrome. It also helps increase vitamin D levels.

In contrast, the bay contains only three glass panels. Hence, they give less natural light than a four-wall bow window. As a result, the bay windows don’t get enough sunlight, but they give more privacy.

Outdoor Views

Large windows give great views of the sky. A bow window gives you a broader panoramic look at your surrounding landscape. However, if you want a clear view of the outdoor area, a bay window is a perfect option. A bow window is better for a larger view offering a more broad view than a bay window.

Exterior Space

A bay window extends from the building by at least 2 feet. They may be a poor choice for buildings located closer to road surfaces and curbs. In contrast, bow windows have narrower profiles up to 4 inches. They need only 11 inches for an 8-foot wide window, making them the better choice for places with space constraints.


Energy-efficient windows are vital if you are looking to save money on your energy bills. Unfortunately, the larger surface area of both windows may affect your energy efficiency. But, with an energy-certified star window, you should be able to save on heating and cooling costs.

Which One is More Expensive Bay or Bow Windows?

Compared to your standard windows, both bay and bow windows are expensive. However, a bow window is more expensive when compared to its counterpart due to its large size. The former is almost twice as big as the latter. Moreover, the installation of a bow window is much more expensive than a bay window. Bow window installations require a new roof and a soffit tie-in to seal the windows against the draft.

Comparing costs: Bay vs. Bow Windows

modern bow window

Bay and Bow windows cost extra in comparison to replacement windows and doors. A bow window is two times larger than the bay window so that the price goes up. The exact pricing will depend on your location on the difficulty of the installation. Knowing the cost for both types will help you make a decision.

A five-panel vinyl bow window is expected to cost an average of $3,600 in materials and labor. An 8-foot vinyl bay window costs an average of $2,600. The cost for a bay or bow window will also depend on whether you choose a bump-out alcove from floor to ceiling. Other costs include flooring, drywall, and molding at a bare minimum. Once you get everything together, your bow or bay window will cost upwards of $8,000 to install and assemble.

Where Should I Use a Bay or Bow Window?

Bow and Bay windows will complement any room in a home. Both provide more light and a better view. In addition, they are available in multiple materials and styles.

Bay window works well in a kitchen, with the extra space used as a breakfast nook for more seating space. They are also helpful above a kitchen sink to give space for plants and an indoor herb garden.


The key factor to installing bay and bow windows is the space both inside and outside. A bay window requires much more space than a bow window. A bow window is preferable when your home is located close to a sidewalk or curb. In contrast, a bay window works if you have space constraints. The windows themselves add extra space.

  • Are you looking for abundant natural light? The vast expanse of a bow window lets in more natural light.
  • Are you craving a view of beautiful nature? Again a large bow window can bring a slice of nature inside.
  • Do you like opening your windows for fresh air? A bay window has an operable panel, while a bow window doesn’t have one.

Hire a professional bow window installation company for faster and better results. Look into quality premium brands such as Milgard and Andersen Windows.