three-part window

three-part window

1. A window having three sashes of the same height and in the same plane; there is a wide rectangular sash at its center and a narrower sash on each side; essentially the same as a Palladian window with the rounded head of the center sash lopped off at the top.
2. Same as treble sash.
References in periodicals archive ?
A professional installer can usually put up a three-part window treatment on one window in about 20 minutes and will charge $40 to $50 (or more) per window.
The central panel of this three-part window is a glassy bay that juts out 3 feet into the view.