American Architectural Manufacturers Association. A national trade association that establishes voluntary standards for the window and door industry. [Link to AAMA site]



The amount of air that passes between a window or door sash and its frame. It is measured in terms of cubic feet or air per minute, per square foot of area. The lower the number, the less air the unit lets pass through.



clad windows and doors – Windows or doors of wood construction covered on the exterior with extruded or roll-formed aluminum. Has a factory-applied finish to deter the elements. Angle bay window – See: Bay window.



Annealing is a process of slowly cooling glass to relieve internal stresses after it was formed. Glass which has not been annealed is liable to crack or shatter when subjected to a relatively small temperature change or mechanical shock. Annealing glass is critical to its durability. If glass is not annealed, it will retain many of the thermal stresses caused by quenching and significantly decrease the overall strength of the glass.



Anodizing, or Anodising in British English, is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The process is called “anodizing” because the part to be treated forms the anode electrode of an electrical circuit. Anodizing increases corrosion resistance and wear- resistance, and provides better adhesion for paint primers and glues than bare metal.



Inside flat trim member which is used under the stool at the bottom of the window.



A unit shaped like a tombstone, has a smooth curve where the head and jambs meet.



An odorless, colorless, tasteless, nontoxic gas that is six times denser than air. Replacing the air between two panes of glass with argon gas reduces temperature transfer, making the surface of the glass inside the house closer to the inside temperature.



Interior or exterior molding often found on older casements or swinging screens. It is attached to doors or side-hinged windows and prevents swing through. Astragal is often used in sliding doors as well to create a tighter fit.



Top-hinged sash. See: Jal-Awning window.