Parts of a Window and Window Frame (Diagrams)

When you’re replacing windows, it’s nice to know all the different parts of the window and window frame. That’s here these 2 diagrams come into play. The first illustrates the anatomy of a window and frame.

The second showcases the anatomy of a cross-section of a three-pane window.

Diagram: Parts of a Window

• Interior Casing: The finished trim or holdings around the window frames. They help prevent cold air from entering as well as add a finishing touch and enhance the overall look of the window.
• Head: The horizontal part of the window frame.
• Muntin: A bar or strip of wood or metal between adjacent panes of glass that create a grid or latticework appearance.
• Sash Lock: The locking mechanism attached to a single-hung or double-hung window.
• Upper Sash (Upper Panel): The upper part of the fixed or movable framework holding the pane of a window.
• Side Jamb: The vertical parts that form the sides of a window frame.
• Stile: Vertical members of the window frame.
• Window Pane: A plate of glass within a window frame.
• Lower Sash (Lower Panel): The lower part of the fixed or movable framework holding the pane of a window.
• Channel: A groove around windows.
• Exterior Sill: The external horizontal bottom part of the frame that protects from water intrusion and can be used as a decorative element.
• Apron: The decorative raised section below the window sill.
• Stool: The bottom horizontal shelf of the window attached to the window sill where the sash descends and where plants may be placed.
• Bottom Rail: The lowest horizontal part of the window frame that connects its vertical parts.
• Top Rail: The top horizontal part of the window frame.
• Head Jamb: The vertical side on the the very top of a window frame where the window sash sits on.

Cross-Section Illustration of a Window

• Air Latch: Makes it possible to keep the window open regardless of the position you set it.
• Aluminum Bracket: Brackets made of aluminium and part of a window bracket system that offsets the window from the wall by a few inches.
• Glass Sealant: A silicone-based product that can take on the form of a liquid, gel or foam and applied to glass surfaces as a protective coating and to preserve its clean and dry exterior.
• Hollow Glass: Window panes made of hollow glass.
• Pane: A sheet of glass in a window.
• Spacer: An insulating glass unit typically made of aluminium that’s sealed between two glass layers and keep glass panes apart.
• Meeting Rail: The horizontal rail of a sash that meets the rail of the other sash when the window is closed.
• Pulley: A simple machine with a wheel and a rope or chain used to lift heavy objects.
• Sloped Sill: The exterior part of the window sill that is designed to be sloped downward to enable water to run off.
• Drain Hole: A short channel where fluids can flow.
• Lift Rail: A handle used to open and close a window that goes all the way across the sash.
• Lower Sash: The lower part of the fixed or movable framework holding the pane of a window.
• Glass Sealant: A silicone-based product that can take on the form of a liquid, gel or foam and applied to glass surfaces as a protective coating and to preserve its clean and dry exterior.
• Bottom Rail: The lowest horizontal part of the window frame that connects its vertical parts.
• Frame: The framework that makes up the window’s perimeter and supports the entire window system.