Window Parts Explained

Exterior Parts of a Double-Hung Window

Thank you Pella for the very complete explanation! If you are considering a fixer upper – or even a resale home that is in good condition, there may be issues which arise concerning the windows. Here is a simple primer of window parts so that when your home inspector tells you that you have a problem with the head of your picture window, you don’t think you need to call a neurologist!

• Frame
  The framework that surrounds and supports the entire window system – comprised of the head, jamb and sill.
• Head
  The main horizontal part forming the top of the window frame.
• Jambs
  The main vertical parts forming the sides of a window frame.
• Sill
  The main horizontal part forming the bottom of the frame of a window.
• Jambliner
  A strip which goes on the sides of a window frame that provides a snug fit for the window sash.

Hardware and Interior Parts of an Architect Series Double-Hung Window

• Balance (Not shown)
  A mechanical device (normally spring loaded) used in single- and double-hung windows as a means of counterbalancing the weight of the sash during opening and closing.
• Sash
  The moveable part of a window made up of the vertical and horizontal frame that holds the glass.
• Check Rail
  On a double-hung window, the part where the bottom part of the upper sash and the upper part of the lower sash come in contact. Also known as the middle of the window.
• Glass
  A framed sheet of glass within a window frame.
• Rail
  The horizontal piece of a window sash – comprised of the lower rail and upper rail.
• Lower Rail
• Upper Rail
• Lift
  A handle for raising the lower sash in a single- or double-hung window.
• Sash Lock
  The locking mechanism used on a single- or double-hung window that engages with the sash lock strike to reduce rattling.

Parts of a Casement Window

• Aluminum Clad
  The exterior wood parts of a window covered with extruded aluminum, with a factory-applied finish to deter the elements.
• Argon (Not shown)
  An inert, nontoxic gas used in insulating glass units to reduce heat transfer.
• Casing
  Decorative molding or framing around a window to cover the space between the window frame or jamb and the wall.
• Fiberglass
  Frame and sash are a five-layer pultruded fiberglass material.
• Hinged Glass Panel
  The glass panel on Designer Series® windows that opens inward to allow access to our snap-in between-the-glass blinds, shades and grilles.
• Lock Handle
  A locking mechanism located on the jamb of a window.
• Operator
  A crank-operated device for opening and closing casement or awning windows.
• Vinyl
  Interior and exterior frame and sash surfaces are extruded rigid PVC.
• Weatherstrip (Not shown)
  A strip of resilient material for covering the joint between the window sash and frame in order to reduce air leaks and prevent water from entering the structure.

Hardware and Interior Parts of a Double-Hung Window with Circlehead

• Fixed Panel
  An inoperable panel of a window.
• Mullion
  A major structural vertical or horizontal piece that combines two or more windows together.
• Grilles
  Decorative pieces that visually divide window panels, giving the glass the appearance of multiple glass panes.

Exterior Parts of a Double-Hung Window with Circlehead

• Mullion
  A major structural vertical or horizontal piece that combines two or more windows together.
• Screen
  Woven mesh of metal, plastic, or fiberglass stretched over a window opening to permit air to pass through, but not insects.
• Weep Hole
  The individual openings provided in the window sill that allow water or condensation to escape.

Thanks to Pella for this explanation of window parts!