Lancet Window: Tall, narrow window with a pointed-arch top, characteristic of Gothic architecture, and often with leaded diamond shaped lights.
Latch:device on the interior face of the sash that retains the window sash in place, it also alow the sash tilt in for easy clening.
Laminated glass:two or more lites of glass and one or more bonding interlayer. The lites and the bonding layer are fused together, considered a safety glass.
Light or lite: Glazing framed by muntins and/or sash in a window or door.
Light shaft: An insulated shaft built to direct the light from a roof window or skylight through the attic to the room below.
Lift rail: A handle or grip installed on the bottom of the lower sash rail of a double-hung window to make it easier to raise or lower the sash.
Low-E Glass: Glass that has a coating with low emissivity that restricts the passage of radiant heat and UV light for better energy efficiency and protection from fading.