What Is a Double Hung Sash Window?

Double-hung sash windows are a popular choice.

The double-hung sash window is a common sight in both new construction and older homes. Two panes rest in their own movable frame and share a larger permanent frame allowing flexibility in opening one pane as little or as much as wanted. Rubber or metal weatherstripping keeps drafts from leaking inside when both framed panes are closed.

What Is a Sash Window?

Older Victorian homes have double-hung sash windows.

Sash simply means frame. Derived from the French word “chassis,” sash became a popular term with the British in building Georgian, Edwardian and Victorian homes in the 19th century. Sash has remained synonymous with a framed window since the latter part of the 17th century. Double-hung refers to two panes that share the same frame and operate independently of one another.

Construction

The sides and top of the double-hung sash window frame, called the jambs, are made of one-inch-thick lumber. The sills that sit along the bottom portion of the window are made of two-inch lumber and are sloped for proper drainage. Springs and balances or compression weatherstripping are fitted along the sides of the frame for tension and counterbalance.

Styles

Muntin bars add style to a home.

Double-hung windows, also referred to as mullion, can be placed independently or along the sides of a larger stationary window to create a balanced look. They can also be placed side by side in a row as seen with enclosed patios. Small wood members known as muntin bars can be used to separate each glass section into smaller sections, which is popular in Colonial-style homes.

Hardware

Hardware for a double-hung sash window consists of sash lifts that are placed on the bottom rail of each frame for easy opening. Some models have finger grooves instead of separate lift mechanisms. Sash fasteners and locks are located on the top rail of the bottom frame to secure the two frames together with an airtight fit.

Today's Double-Hung Sash Window

Many double-hung sash windows of today can be removed for maintenance or lifted inside for easy cleaning. Many manufacturers have also replaced the wood frame with durable plastic material that will not rot and requires little maintenance.

References

• Origin of Sash Window
• History of the Sliding Sash Window
• Double-Hung Window Construction
• The Origin of the Sash Window