Don’t get overwhelmed. Fenster is here to help you understand window replacement.

Window replacement can sound overwhelming, especially if your home has a large number of windows. Not only can it get expensive, but it can also be time-consuming and require a substantial amount of work that can disrupt your daily life. 

In some cases, detailed wood windows are difficult to replace or match if only one or two windows are in need of replacing. Besides, what if only one or two windows are showing signs of aging or aren’t working properly? 

Before we dig into how to replace a window sash rather than the entire window, let’s take a closer look at the anatomy of sash windows, their history, and how to tell when it’s time for a sash window replacement.

What Is a Window Sash?

A window includes a variety of components such as the frame, the grilles that hold the glass, the glass itself, locking mechanisms and the sash. Put very simply, the sash is the part of the window that moves and holds the glass panes together. 

The sash of a window slides open vertically or horizontally in a double-hung window. In casement windows, it opens vertically or horizontally with a crank mechanism. 

The History of Sash Windows

As with many elements of architecture, it’s difficult to pin down exactly where and when sash windows were invented. By some accounts, they originated in the 17th century in Holland and England. However, others attribute their invention to British architect Robert Hooke who, along with Sir Christopher Wren, was influential in the rebuilding of London after the Great Fire of 1666. 

Regardless of their origin, the British are credited with refining the design and including a system of weights and pulleys located in the frame that allows the windows to be opened and closed vertically without an external support mechanism like a series of holes and rods or a stick — though you may see sticks or rods used to prop open a malfunctioning or worn out sash window. Before the weight and pulley system, sash windows typically opened horizontally.

Modern sash windows use a balance — a spring mechanism in the jamb liner — to keep the sash up.

Parts of a Sash Window

Sash windows are an intricate combination of interconnected components. These are the essential parts that make up a full double-hung window system:

• Frame: The exterior frame of a sash window that is recessed into the exterior wall and holds all of the remaining parts of a sash window

• Head: The upper, horizontal trim piece

• Casing: The decorative molding around the exterior of the window that hides the space between the frame and the wall

• Stool: The bottom lip on the exterior of the window, essentially the exterior version of the window sill

• Apron: The trim below the window stool that is usually wider than the rest of the trim and used to cover a gap between the frame and wall

• Sash: The operable part of the window that opens and closes

• Rail: The horizontal side of the sash frame

• Stile: The vertical side of a sash frame

• Grilles: The strips of wood or other material that form a grid and hold the glass in place — early sash windows contained multiple panes of glass held together with grilles. 

Today’s sash windows are typically made with one piece of glazing and the grilles are largely decorative

• Glass: Also called glazing, the glass pane or panes that make up the window’s sash

• Lift: The handle that assists the user in opening and closing the window

• Sash lock: The mechanism that locks the sash to prevent it from opening

Casement windows have many of the same parts as a double-hung sash window with a few exceptions:

• Crank: Replaces the lift to open and close the window

• Mullion: The strip of wood or other material that seals the window when it’s closed

• Window hinge: The hinge that allows the window to swing open and closed

Window Sash Replacement: When is the Time?

Exterior materials age and weather at different rates depending on their positioning around a structure. Areas of the house that are exposed to the sun and those that are exposed to shade will naturally weather differently. For example, areas in the sun can experience fading while areas in the shade are more prone to rot from moisture or degradation from moss, mildew or algae growth.

This means that the likelihood of needing to replace all of your windows at the same time is low. Sure, you may want to do a full upgrade and reset the timeline on window wear and tear by doing a full replacement on every window. However, it’s more likely that you’ll need to replace windows at different times as they age at different rates.

How Fenster Can Help Save Time and Money

To help save you time and money, Fenster allows you to replace the window components that need to be replaced rather than having to replace the entire window.

We sell replacement parts for windows whose manufacturer is no longer in business. This is important because if you have a home with older windows, our products allow you to replace the windows that you need while avoiding having to buy all new windows. 

We produce replica windows that will match the original, but without the poor materials or design flaws that have resulted in damage. Our ability to replicate both double-hung and casement window sashes means that you can rest assured that your home’s windows will match and reflect the beauty of the originals. Whether you’re a seasoned DIYer or new to the process, our ordering guide will walk you through how to take measurements and place your order. 
Reach out to our team today to discuss how we can help restore your windows to their original beauty.