What is a Double Hung Window?

Windows serve many functions.  They provide natural lighting, ventilation and visual appeal.  There are many window options that serve all of these purposes.  Perhaps the best known and most widely used is the double hung window.  The materials used to produce double hung windows have changed through the years, but the design and operation remains the same.

Origin of the Name

Double hung windows are named for the two main components of the unit.  There is a top sash and a bottom sash that meet in the middle.  A sash is a moving piece of glass framed with wood, aluminum, etc.  The two sashes are hung, one above the other, in a single casing; hence the name double hung window.  This is a highly popular window product that can be found in most homes.

Description

Double hung windows have a single casing that functions as a track for the sashes.  Sashes can be a solid piece of glass; multiple glass panels fit into frames; or two solid glass sheets with a decorative frame between.  The casing, sashes, screen and all applicable hardware are manufactured as a single unit.  Replacement parts are usually available from the manufacturer in case of defect or damage. 

Operation

Double hung windows typically have a locking mechanism in the middle where the two sashes meet.  When unlocked, the bottom sash simply slides up and down to open and close the window.  Some double hung windows have an interior accessed mechanism for tilting the bottom sash open so the outside of the window can be cleaned from the inside of the building.