Curious about the anatomy of a window? We have put together an illustration of double-hung windows along with the terms that describe the anatomy or parts for replacements or new construction windows. We have also included definitions of applicable terms if you scroll down.
Anatomy Of A Window
Definitions Behind Window Anatomy
Apron – Horizontal piece/slat of trim beneath the window sill.
Argon Gas – a type of gas that is used to replace the air in double or triple glazes to increase the energy efficiency by decreasing the amount of heat loss.
Center Hung Sash – a sash that is hung or mounted on pivot pins in the center so the sash can be pivoted open in order for easy cleaning.
Frame – the fixed part of windows (the perimeter) within which the sash or panes of glass are mounted.
Head – the frame along the top. Also called the ‘header’.
Head Expander – u-shaped filler (usually made of vinyl) on the head.
Jamb – the frame members on each vertical side (similar to the ‘head’ which is the frame member on the top of the window).
Main Frame – the main parts of a frame (the jambs (sides), head (top) and sill (bottom)).
Meeting Rail – horizontal rails of two opposing sashes that meet when the unit is closed.
Mullion (or Muntin) – separator (either vertical or horizontal) between two windows.
Rail – the horizontal member of a sash on the top or bottom.
Sash – the part of windows that contains the panes of glass. It can be fixed to the frame or can be movable.
Sash Lock – a lock that works by having one portion of the lock on each of the meeting rails of windows (a cam lock on the lower sash and the matching receptacle on the upper sash).
Sill – the horizontal shelf that sits along the bottom interior of a frame.
Weep Hole – small holes in the exterior sill that encourages water to drain.
Related Topics
Window Replacement Cost Estimator
Photos And Pictures
Casement Windows Prices
Library | Glossary Of Terms By:
Energy Efficiency and Performance – Explore technical terms in this section, things like U-value and wind load.
Parts and Features – Find great terms in here on all of the different parts that go into making solid or ineffective windows.
Installation And Accessories – Discover contractor, installation and accessory information.
Types And Styles – Explore the many materials and frames available. In addition, find a brief explanation of all the windows out there; double hung, casement, awning, gliders, etc.
