- Awning window: An operation window that is hinged from the top and rotates outward.
- Argon Gas: An inert gas that is pumped into a sealed unit usually in combination with low to help reduce heat loss in the home.
- Astragal: The center member of a double door, which is attached to the fixed or inactive door panel.
- Bay window: A composite of three or more windows, usually made up of a large center unit and two flanking units at 30°, 45° or 90° angles to the wall.
- Bow window: A composite of four or more window units in a radial or bow formation.
- Brick mould: Outside casing clipped into and around window as an optional trim and through which nails are driven to install the window.
- Casement: An operating window that rotates out like a door.
- Casing: Inside casing is a flat, decorative moldings which covers the inside edge of the jambs and the rough openings between the window unit and the wall. Outside casing (or Brick Mould) serves the same purpose, while it also is an installation device through which nails are driven to install the window unit into the wall.
- Check rail: On a double-hung window, the bottom rail of the upper sash and the upper rail of the lower sash, where the lock is mounted.
- Circlehead or Roundtop: A generic term referring to any of a variety of window units with one or more curved frame members, often used over another window or door opening.
- Clerestory: A window near the top of an outside wall.
- Cottage double-hung: A double-hung window in which the upper sash is shorter than the lower sash.
- Cripples: The short 2" x 4" members used to frame under the sill or above the header in a rough opening for a window in a frame wall.
- Curb: A watertight wall or frame used to raise slope glazing above the surface of the roof as a preventive measure against water leakage from melting snow or rain run-off.
- Dormer: A space that protrudes from the roof, usually including one or more windows.
- Double glazing: Use of two panes of glass in a window to increase energy efficiency and provide other performance benefits.
- Drip cap: A moulding placed on the top of the head brickmould or casing of a window frame.
- Emissivity: Tendency to emission; comparative facility of emission, or rate at which emission takes place; specif. (Physics), the rate of emission of heat from a bounding surface per degree of temperature difference between the surface and surrounding substances (called by Fourier External Conductivity).
