Apron

Related terms

• Sill

  The horizontal bottom member of a window frame, sloped to shed water away from the building.

• Stool

  The interior horizontal shelf at the bottom of a window, what people commonly call the inside sill.

• Argon / Krypton Fill

  Inert gas sealed between glass panes; denser than air, it slows heat transfer. Krypton outperforms argon in thinner triple-pane cavities.

• Aluminum Window

  A strong, slim-profile metal-framed window; without a thermal break it conducts heat and is less efficient, so used mainly in warm climat…

• Astragal

  The vertical molding/seal where a pair of doors meets, closing the gap and providing a stop and weather seal.

• Air Leakage (AL)

  The rate of air infiltration through a window assembly; lower is tighter and more efficient.

• Awning Window

  A window hinged at the top that swings out from the bottom, shedding rain so it can stay open in light weather. Often used high on walls…

• ADA Door Clearance

  Accessibility requirements for door width (32 in. clear minimum), maneuvering space, threshold height, and lever (not knob) hardware.