Glossary of Terms

During your window or door project you will hear many unfamiliar terms used by architects, contractors, dealers or manufacturers. We hope this glossary of terms will prove a useful tool.

Casement Window
A window that is hinged to open either outward, inward or is fixed. Hinged casement windows include:

• Awning
  Hinged at the top
• Center Pivot (dean)
  Rotating on a center horizontal or vertical axis,
• Hopper
  Hinged at the bottom.

Clad
An abrasion resistant, pre-finished, extruded aluminum material put on exteriors for a low maintenance finish.

Double-Hung Window
A window with two movable sashes that slide in a vertical track.

Double-Paned/Insulated Glass 
A window pane where two panes of glass are set together to improve insulation.

Friction Hinge
Hardware, which allows casement windows to open and stay in place.

Glass Types:

• Annealed
  Poor sound barrier with weak insulating properties, commonly found in older homes
• Laminated
  Two pieces of glass bonded together with a Polyvinyl Butyral (PVB) interlayer, for sound attenuation, UV reduction, security and earthquake safety
• Low-E
  Less penetration of UV light rays, improved insulation, higher R rating, most often found in insulated glass units
• Tempered
  Safety glass that resists breakage,

Jamb
The wood surround (top, two sides and the sill) to a window or door that fits into a rough opening in a structure. A sash fits inside the jamb.

Lite
A piece of glass surrounded by wood, a pane. Often used when referring to multiple panes.

Muntins (Mutts)
The narrow strips of wood between lites.

Ogee Lug
A curved ornamental part that hangs down from the lower corners of upper sashes in double-hung windows.

Pane
As in window pane, also called a lite.

Parting Bead
A small strip of wood that runs vertically to separate the upper and lower sash of a double-hung window.

Pulley
A wheel with a grooved rim set at the top of a jamb; used for guiding the sash cord in double-hung windows.

Putty/Glazing Compound
Air-tight, water-tight sealant used on window exteriors.

Rail
A horizontal member that fits between vertical members to form a window sash. There is a top and bottom rail on each window sash.

Sash
The wood that surrounds a pane or panes of glass. Consists of a top rail, bottom rail, a stile on each side and muntins if more than one lite.

Sash Cord
Small ropes that connect controlling weights to the sashes of older double-hung windows.

Sill
The horizontal member at the bottom of a window frame.

Simulated Divided Lites (SDL)
Muntin bars are permanently adhered to both sides of a piece of glass to give the impression of separate panes.

Stile
The vertical member of each side of each sash, joined together by stop and bottom rails.

Stool
The shelf-like wooden member on the inside of a window commonly referred to as the “window sill”.

True Divided Lites (TDL) or Authentic Divided Lites (ADL)
When wooden muntins surround individual panes of glass in a sash.