Transom

Related terms

• Triple-Pane / Triple-Glazed

  A three-pane insulated unit with two gas-filled cavities for superior insulation and sound control, used in cold climates and high-perfor…

• Threshold

  The bottom member of an exterior door opening, often adjustable, that works with the door bottom and sweep to seal out water and air.

• U-Factor

  The rate of non-solar heat flow through a window; lower means better insulation. The primary winter-performance metric on the NFRC label.

• Thermal Break

  An insulating barrier within a metal frame that interrupts heat conduction, substantially improving an aluminum window's efficiency.

• Vinyl Window

  A PVC-framed window — low cost, low maintenance, good insulation. The dominant residential replacement material; quality varies widely by…

• Tempered Glass

  Heat-treated safety glass that is much stronger and breaks into small blunt pieces. Code-required near doors, floors, tubs, and large low…

• Visible Transmittance (VT)

  The fraction of visible light a window transmits (0–1); higher means a brighter, clearer view.

• Strike Plate

  The metal plate on the jamb the latch and bolt engage. Long screws into the framing here are the single cheapest security upgrade.