Do you ever lay awake at night thinking about windows?

No, not the PC software. I’m talking about the opening in your wall that lets you see through to the other side.

Windows may not be the first thing you daydream about, but when you realize how many different types of window designs exist, why they exist, what their applications are and how each type of window is used, you may find them more fascinating than you realized.

As you scroll down this page, you’ll find illustrated and photographic examples of all the most common (and not-so-common) window types around the world.

1. Single-Hung Window

Single-hung windows have two sashes (the part of the window that holds the glass pane): one fixed sash on top and one moveable sash on the bottom, which can slide up and down. This makes single-hung windows rectangular in shape in a vertical orientation.

Since they don’t open outward, they’re ideal for rooms facing constrained pathways and streets. At the same time, it goes well with small spaces where an upper sash would be difficult to open, like above a kitchen sink or a bathtub. Single-hung windows are also some of the common window types installed in new constructions, office spaces, and residential complexes.

Single-hung and double-hung windows are collectively known as “sash windows.” Their history can be traced back to Georgian and Victorian houses in England.

2. Double-Hung Window

Double-hung windows are similar to single-hung windows, but instead of only the bottom sash being moveable, both sashes can be moved. This makes a double-hung window superior to a single-hung in terms of ventilation, as the two sashes can be moved independently, even tilted inward for cleaning. It makes double-hung units useful in areas that require good ventilation, including bathrooms, kitchens, and bedrooms, and they can be made of almost any material—from wood to vinyl.

Double-hung windows have been beautifying and adding character to homes for centuries. One of the most popular window types in the world, double-hung windows can be used in any type of architecture, from traditional to contemporary.

3. Hopper Window

Hopper windows are like awning windows. They have hinges on either the top or the bottom, and they can open inward, from 45 degrees to all the way to 90 degrees. They’re commonly found in basements and on top of walls near where the ceiling meets the wall, so opening it all the way may pose a safety risk.

These windows are usually in a horizontal rectangular shape and constructed to withstand strong winds. Hopper windows are often found in small bathrooms, kitchens, and basements, where ventilation can be at a premium. Because of their expansive panel that opens in one go, these windows offer ease of access and help improve air circulation within any room.

Hoppers get their name from their shape when opened, which is like a hopper or a chute.

4. Casement Window

One of the most popular window types among U.S. homeowners, casement windows are hinged at the side, allowing them to swing outward; this makes operating one similar to opening a door. A casement window can be operated by a handle or lever, usually at arm level, and a fold-away mechanism called a casement stay or crank at the bottom to hold the window in an open position despite the wind.

Many homeowners prefer casement windows because they let in an abundant amount of sunlight and fresh air. Moreover, casement windows are highly energy-efficient, as the sash is flush to the window frame when closed, preventing air leakage. Due to their structure, these windows are ideal for difficult-to-reach areas like over the kitchen sink or in cramped corners. Casement windows are available in numerous materials, including wood, fiberglass, and vinyl.

5. Center Pivot Window

True to their name, center pivot windows have sashes that pivot in the center of the frame when opened, which makes them project half in and halt out of the room. This unique structure brings plenty of light and fresh air into any area, although some modern double-hung windows have also made strides into incorporating this mechanism into their panels.

Center pivot windows are also usually equipped with top-operated panels, making them easy to open and access. Whether standing or seated, users can easily enjoy great views with this window type.

6. Transom Window

Transom windows (or transom lights) got their name from where they’re usually installed—over the transom, the area over a door or a big window.

Transom windows came into being during the medieval ages, especially in the 1300s, when a space over a door can bring daylight in, while its height can provide some semblance of privacy. Traditionally, transom windows come in a standard rectangular shape, but most modern transom windows today are available in a wide range of shapes and sizes. They usually don’t open, but some window manufacturers can make transom windows that can be operated for additional ventilation.

Fanlights or lunette/half-moon windows are a subdivision of transom windows, which are arched and decorative.

7. Bay Window

A bay window projects outward beyond the wall, similar to bow windows. These usually consist of three window panels, of two flanking units and one central unit. A part of Renaissance architecture, bay windows are usually found in a great hall of a lord or noble, opposite the entrance to the room. Bay windows on a second story are also called oriel windows.

Polygonal bay windows are the most common, in which there are two or more flanking units and a central unit that’s fixed and can’t be operated. The biggest benefit of bay windows is that they allow for more space on the interior. This extra space—the so-called “bay”—is commonly utilized for additional seating, but it can be used for other things as well, such as a cozy nook or a reading area.

8. Bow Window

Bow windows are similar to bay windows, but these are often larger and wider and are usually in an arc shape—which looks like a bow.

The benefits of bow windows are the same as that of bay windows, notably the additional interior space and admittance of more light than a row of windows flush with the wall. In fact, some even call bow windows the same as a bay window, only with more window units (which creates a more pronounced curve). Like bay windows, bow windows form a ledge inside, which can be used for seating and storage.

9. Jalousie Window

Also known as a louver window, jalousie windows take their name from the French word for “jealousy,” as it’s meant to screen something from view. Jalousie windows were in vogue in France in the 1700s, though it was only patented in 1901.

Jalousie windows are made up of multiple slats of glass and work just like plantation shutters. You operate it by turning a crank, which tilts and opens the slats all at once because they are joined with a track. One of their distinct benefits is that they can be tilted slightly to let in cool breezes while protecting the interior from rain, and an option to open the slats entirely to improve air circulation within a room, especially during summer months. The design of jalousie windows is versatile enough to suit any architectural style, but they are more common in tropical climates or in dwellings with no air conditioning.

10. Garden Window

Garden windows are an offshoot of bay windows; in fact, they’re practically the same thing, only that the “bay” is large enough to hold one or two potted plants. They are shaped like a box that protrudes outward from the wall at about 1 and a half feet to 2 feet, covered in glass all around, which increases the greenhouse effect. The added space of a garden window can easily be turned into a nook, which homeowners can use to display flowers or grow a mini garden.

11. Glass Block Window

Glass blocks are a combination of individual blocks sealed together with mortar. Most property owners use them because of the privacy they offer; the translucent, thick blocks of glass allow light into the room without letting people see through them. They were highly popular in the early 1900s, allowing early 20th century factories and warehouses access to cheap lighting when the glass blocks are installed on walls and as skylights.

Due to this unique functionality, glass blocks are often used in areas where privacy is a concern, such as bathrooms. They are also a good option for rooms that require just the right amount of light, including basements and kitchens. Modern glass blocks come in an array of styles and dimensions, making them an effective aesthetic element, though some interior designers prefer other alternatives in terms of combining lighting and privacy.

12. Storm Window

Storm windows are basically secondary windows usually installed on the outer side of an existing primary window, though you can order ones that can be installed on the interior as well. Storm windows are designed mainly to protect against the harmful effects of weather. For that purpose, they create a reliable seal that keeps the elements at bay while regulating interior temperature. For this reason, they are commonly manufactured out of durable, straightforward materials such as glass, rigid plastic, and flexible plastic sheets.

13. Egress Window

Egress windows are large enough that they can function as emergency exits and are normally required for basements. These windows open to a small area outside the house—small enough to be inconspicuous but large enough to accommodate an adult. They also serve as an entry point for emergency teams who find that the normal entry point is blocked or inaccessible.

The International Residential Code mandates egress window dimensions for safety and consistency across any type of dwelling. Some requirements include the width of the egress window (at least 20 inches), height (at least 24 inches), opening area (5.7 square feet), and sill height (at least 44 inches from the floor).

14. Skylight Window

Skylights (also called rooflights) are windows installed in a roof or ceiling, admitting plenty of natural daylight into a structure. Any property owner can turn average rooms with limited sunlight into bright, light-filled spaces using their expansive glasses. While glazed skylights (skylights employing glass, as in modern windows) were a relatively modern invention, open skylights existed as far back as the classical period, such as in the oculi of the Hellenistic and Byzantine architecture.

Aside from the fact that skylights offer a wonderful view of the sky from the outside, they also help save energy by naturally brightening dark areas and reducing the use of artificial lights. This type of window is commonly seen on cabins, vacation houses, and modern homes. Some skylights are also used for passive heating or fresh air exchange.

15. Round Window

Round windows, also called rose windows, are circular windows with wrought iron arms radiating from the center. These were popular in Gothic architecture, especially in churches, but they have also been used in homes for generations. Like skylights, round windows have a common parentage—small holes set into roofs or walls in the classical era, such as in the Pantheon, called oculi (singular, oculus).

Suitable for both small and large rooms, these windows can be customized in terms of color, pattern, finish, and grille design to match any architectural need. One of the unique advantages of round windows is that they establish a focal point in a room, allowing property owners to set the mood for their spaces.

16. Radius Window

Radius windows have an arched shape on the top half and a vertically oriented rectangular shape on the bottom half. Some homeowners simply call them arched windows. Because of its hybrid nature, radius windows can be used to either emphasize lines (for curvy architecture) or bring softness (for architecture that’s all about edges, such as in modern and post-modern homes).

These windows add glamor to any home or building and often function as an uncovered transom, bathing interior spaces in natural light. Unlike other window types, radius windows can be made operable to improve ventilation or fixed to only let in light, or subdivide the top half to be fixed and the bottom being operable (or vice versa).

17. Lunette (Half-Moon) Window

In architecture, a lunette is a type of structure meant to resemble a crescent or semi-circle shape, often seen on top of a doorway. Lunettes can be used to display sculpture or set with glass, which is from where the lunette window comes in (see Transom Window).

Half-moon windows can be seen on many traditional and historical architectures, such as Victorian and Federal Colonial houses, neoclassical buildings, as well as cathedrals, and museums.

18. Dormer Window

Dormer windows (or simply dormers) are windows that project vertically from a sloping roof. They are not set into the roofing at an angle; rather, they are set out from it, making them one of the most distinctive aesthetic elements of homes that have them. Dormers came from the French word “dormeor,” which means sleeping room. Dormer windows were originally used as windows for an attic-like space beneath the roof, used as sleeping quarters in 1500s England.

Dormers can take the form of various window types, such as double-hung, casement, and even arched. Aside from being a great source of daylight, they are also known for the extra space they create, which homeowners can use for different purposes.

19. Oriel Window

An oriel is a variation of a bay window that is commonly used in the upper floors supported by corbels, brackets, or any other similar structures (see Bay Window). It gives a panoramic view of the outside while adding elegance to the property. Like bay windows, oriels extend the room’s interior space to which they are attached, often a nook adjacent to the interior walls of the window.

Oriels are common on Queen Anne buildings, enhancing their architectural symmetry, which is a distinct feature of this style.

20. Cottage Window

A common subtype of double-hung windows, cottage windows feature an upper sash that’s remarkably shorter than the lower one. Aside from this, most of the cottage windows’ features resemble those of double-hung windows, with both sashes operable to let fresh air in and simplify maintenance. What sets them apart from double-hung windows is that their sashes are split asymmetrically; the top sash is often smaller, at a ratio of 40:60. The top sash may also have grilles, which the bottom may not have.

Cottage windows never go out of style, which is why they are popular not just in traditional buildings like Georgian and Tudor homes but also in modern and contemporary homes. Cottage windows come in a range of materials, including wood, vinyl, and aluminum.

21. Two-Panel Slider Window

Quite literally, two-panel sliding windows, also double horizontal sliders, are sliding windows that feature two sashes that can be opened by sliding from side to side. Typically, horizontal sliders only have one operable slider. This makes a two-panel slider superior in terms of accessibility and ventilation. But, like a horizontal slider, they’re space-saving, as they do not take up any clearance space when opened.

Today, most two-panel sliders are equipped with double locks and double weatherstripping to keep the interiors safe from harsh elements. Simple and elegant, they complement both classic and modern architecture.

22. Three-Panel Slider Window

Three-panel sliders are wider than their two-panel counterpart, which means they offer a more panoramic view of the outdoors. At the same time, they provide superior ventilation when fully opened. This type of window has a fixed middle, while the other two on the sides slide to the center to open.

Apart from the extended panels, it comes with all the advantages of a two-panel slider, such as low maintenance, ease of use, and space-saving features. PVC and metal are some of the most common framing materials used for this type of sliding window.

23. Picture Window

Picture windows have thin frames and large glass areas that provide homeowners with sweeping, gorgeous outdoor views, much like a huge picture frame. They can’t be, which is why they’re not common in small rooms or cramped spaces. Instead, they are often seen in large areas such as living rooms and master bedrooms.

What they lack in ventilation, though, they make up with energy efficiency. Picture windows have tight seals around their edges, preventing energy leaks. Their expansive glass areas also let in lots of sunlight, which helps minimize reliance on artificial lighting during the day.

24. Fixed Window

Fixed windows are an umbrella term for all windows that can’t be operated, such as a picture window. These windows are mainly used for letting in light and providing picturesque views; they can come in many shapes and sizes.

The difference between them lies in the size of their frames. Fixed windows have a more exposed window frame, making them look more striking and more defined. This is one of the reasons they are popular in modern, minimalist homes; they add visual interest to an otherwise simple exterior. While their glass is not as expansive as picture windows, they still offer more light and views than other window types.

25. Awning Window

Awnings are similar to hoppers, except that instead of opening inward, they tilt outward strictly from the top. Awning windows are so-called because they create an “awning” when opened, which prevents rain from coming into the room and yet allows fresh air in.

Awning windows are operated with a turn of a fold-away crank. Like hoppers, they are also used in basements, but awnings are also found as near-roofline height windows for warehouses and storage sheds. They are also placed above certain window types, such as picture windows. This position allows them to maximize lighting.

26. Tilt & Turn Window

Popular in Europe (and not so much in the U.S.), tilt & turn windows are among the most exceptional window types in terms of operation. These windows feature a large sash, with thick frames on four sides. This window type can take three different positions:

• Closed and locked, where they essentially function as picture windows that provide unobstructed outdoor views.
• Open position, where they turn open from their side hinges, like a door.
• Tilt position, where they mimic the functionality of hoppers, tilting in from hinges on the bottom part of the window.

This allows this window to become two windows in one: a casement and a hopper window, depending on what you need. Most tilt & turn windows have a unified mechanism that allows both tilting and swinging.

27. French Doors

French doors, also known as French windows, are operable units that are traditionally hinged on the side, opening onto a patio, garden, and building entrances. Due to their large size, they let in the maximum amount of light into any room.

Originally, French doors were constructed using wrought iron and wood before glass and other modern materials were introduced. Hailing from 16th century France—hence their name—the popularity of French doors soon spread across Europe and beyond, making them one of the most common choices in homes today.

28. Palladian Window

Named after its inventor, 16th century Venetian architect Andrea Palladio, Palladian windows are among the most stunning pieces one can add to a home or building. Palladian windows are divided into three parts: a big, arched window at the center and two smaller rectangular windows on each side. They follow the “Palladian motif,” or three-part architectural pieces popular in England in the 1600s and 1700s.

Due to their large, Renaissance-era design, Palladian windows are great for equally huge and dramatic structures. They are also called Serlian windows or Venetian windows.