What Is a Window Sash?

By Amanda Lutz Updated April 30, 2024

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A window sash is a frame that holds a window’s glass panes. Some sashes are stationary, but others move on tracks within a window’s frame to allow you to open and close your window. Window sashes play essential roles in ventilation, energy efficiency, and the overall look of your home. Learn more about sashes and the different types available in our guide.

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Window Replacement Cost

Replacement windows on average range from $300 to $1,200.

Windows with fixed top sash and bottom sash that slides up, sash divided by white grilles a surrounded by white elegant frame horizontal white vinyl siding on a new construction residence
Single-Hung Windows

Single-hung windows on average cost $150 to $400 per window.

Energy Efficient Upgrades

Double-pane installation typically ranges from $450 to $1,000 per window.


What Are Window Sashes?

Window sashes are the framework within the larger window unit and hold glass panes in place. Sashes can be movable or fixed, and you can open, close, or tilt them to adjust ventilation and access. Many windows have an upper sash and lower sash, which may lock with a clasp or latch.

Sashes come in many shapes and sizes to match different window designs, architectural styles, and functional needs. They may be rectangular, square, arched, or even triangular. Sashes are available in vinyl, wood, and aluminum windows.

Importance of a Window Sash

Window sashes frame and secure panes of glass, but they also contribute to the function and comfort of your home. These parts of a window are important for:

Window Sash vs. Window Frame

The window sash and the window frame each have different, distinct roles in creating a functional window. Read about how they’re different below.

The window sash’s primary function is to hold glass panes, so it may contain framing elements such as stiles or rails around the glass.

  • Appearance: The sash is the visual frame that holds the glass panes. It comes in many shapes and sizes.
  • Materials: Sashes are usually made from wood, vinyl, or aluminum, depending on the budget, features, and a homeowner’s desired aesthetic.
  • Role: The sash is the moveable part of the window. It opens and closes, ventilates, and offers access to the outdoors.

The window frame provides the overall structure and support for the window. It’s fixed to an opening in the wall, attached to the building, and holds the sash or sashes in place.

  • Appearance: The frame forms the outer border of the window and is usually wider than the sash. It creates a secure opening in your wall.
  • Materials: Frames are made from the same materials as the sash. Some window frames may also include fiberglass or composite materials for added strength and durability.
  • Role: The window frame is the stationary part of the window and is affixed to the wall. It provides structural support for the entire window unit and secures the sash within its frame.

How Does a Window Sash Work?

Traditional sash windows feature one or two vertically sliding slashes. Each sash fits into a groove within the window frame. These windows, which are common in Victorian homes, may use a weight and pulley system to open and close. Cast iron or lead weights sit in the frame, and connect to sash cords. The cords run over the pulleys at the top of the frame so that the weights drop as you raise the sash. This counterbalances the sash, and makes it easier to open the window, and keep it in place. Modern sash windows replace the weight and pulley system with a spring mechanism.

Horizontal sliding windows are more common in newer homes. They feature two or more sashes that slide horizontally on tracks within the frame. Sashes glide smoothly thanks to rollers on the bottom. A locking mechanism secures the window sashes when they’re closed.

Both vertical and horizontal sliding sashes may feature tilting latches, which allow homeowners to tilt windows inward. This makes it easier to clean the exterior glazing.

Types of Window Sashes

Window sashes come in various styles, each offering unique advantages and aesthetic appeal. Consider the different window sash varieties below if you’re looking for new windows or window replacements.

Awning Sash

These sashes have a hinge at the top, which allows the window to open outward from the bottom. The sash creates an awning over the window opening, ventilating the home, even when it’s raining. Awning windows are typically small, though, so they only offer a fixed amount of ventilation.

Source: Adobe Stock

Casement Window Sashes

Casement windows have hinged sashes that open outward like a door and offer excellent ventilation. They’re also easy to clean. Casement sashes require plenty of clearance outside the window to properly open, so they may not be suitable for all homes. They’re popular in craftsman-style bungalows and some contemporary houses.

Source: Adobe Stock

Double-Hung Window Sashes

Double-hung window sashes feature two vertically sliding sashes. They’re easy to clean and great for ventilation because you can open the top, bottom, or both. Traditional double-hung windows, which are common in Victorian and Georgian-style homes, may require more maintenance than other models.

Source: Adobe Stock

Horizontal Sliding Sash

Horizontal sliding sash windows have two or more sashes that slide horizontally on tracks within the window frame. They’re great options for wide openings or areas where you want an unobstructed view. These are popular in modern homes surrounded by picturesque landscapes.

Source: Adobe Stock

Single-Hung Window Sashes

Single-hung windows feature one vertically sliding lower sash and a fixed upper sash. They’re more affordable and easier to operate than the double-hung version and provide excellent ventilation for a home. However, they can be tricky to clean, as reaching the upper window glass is difficult. They’re common in bungalows and ranch-style homes.

Source: Adobe Stock

Tilt-and-Turn Sash

These are more expensive and less common sash windows. They combine several sash functions and tilt inward for ventilation and outward like a casement sash. They ventilate well and are easy to clean.

Source: Adobe Stock

Window Sash Maintenance

Your sash windows won’t need much maintenance, but a little bit of elbow grease can help extend their life span. Follow the tips below to keep your windows in top condition.

What are Some Common Issues of Window Sashes?

Window sashes can develop issues over time, even if you regularly clean and maintain them. Below are some common issues and how to solve them.

Can’t Unlock the Sashes

A worn-out or misaligned locking mechanism can make unlocking or locking your sashes difficult. Try cleaning the mechanism and the area around it, then lubricating the clasp or latch. If you think the lock has been painted shut, strip the paint off. If that doesn’t work, you may need to replace the lock.

Damaged Sash Components

If a sash’s weights, pulleys, or springs become damaged, your window may become difficult to keep open. Minor repairs, such as tightening loose screws and replacing fasteners, are easy to perform as do-it-yourself tasks, but broken cords, weights, and springs may require the help of a professional.

Sticking Sashes

Dirt buildup and warping can cause your sash to stick or drag when you open and close your windows. Clean the tracks or the groove in the window frame, then apply a lubricant such as silicone spray to help the sashes glide more easily. You may need to replace sashes that are severely warped.

Our Recommendation

Window sashes are more than just the frames that hold glass in your windows. They facilitate ventilation, protect your home from the effects of wet weather, and change your home’s aesthetic. Understanding the different types of sashes can make replacing your windows much easier.

Regular maintenance is key for keeping your window sashes working smoothly. Simple steps such as cleaning, lubricating, and inspecting your sashes can help prevent costly window replacements. By taking good care of your window sashes, you can enjoy a comfortable, beautiful, and energy-efficient home for years to come.

What Is a Window Sash FAQ

Why is a window sash important?

A window sash is important because it holds the window’s glass in place, allows ventilation in the home, and contributes to the overall look of your property.

When should a window sash be replaced?

A window sash should be replaced when it’s been severely warped, damaged beyond repair, or if the glass panes become foggy because of a broken seal.

How do you maintain a window sash?

Maintain your window sash by regularly cleaning it, lubricating the moving parts, and inspecting it for damage or worn weatherstripping.