Witch window
In American vernacular architecture, a witch window (also known as a Vermont window, among other names) is a window (usually a double-hung sash window, occasionally a single-sided casement window) placed in the gable-end wall of a house and rotated approximately 1/8 of a turn (45 degrees) from the vertical, leaving it diagonal, with its long edge parallel to the roof slope. This technique allows a builder to fit a full-sized window into the long, narrow wall space between two adjacent roof lines, where a window would not otherwise fit.
Depending on the width and length of the wall between the roof lines, a witch window could be either narrower or wider than the windows on the rest of the house, although a matching sash window of the same size is the most common example. There are even rare examples of non-quadrilateral witch windows where an arch window originally over a doorway may be inserted awkwardly into a roof line just like a rectangular window.
Witch windows are found almost exclusively in or near the U.S. state of Vermont, generally in the central and northern parts of the state. While rare examples of these windows can be found in neighboring states such as New Hampshire, the sheer ubiquity and density of witch windows is unique to Vermont alone, where the yeoman farmers in the remote and rugged reaches of the state repurposed windows out of necessity. They are principally installed in farmhouses from the 19th century, and can be found less frequently in new construction, often deliberately included to celebrate the novelty of the witch window itself. The persistence of the witch window into contemporary times is a testament of the resourcefulness and Yankee ingenuity of rural New Englanders, to whom the idea of wasting a perfectly good window was completely out of the question.
While certainly unusual in appearance and unfamiliar to most people outside of Vermont, witch windows are popular with tourists and residents alike, and serve as a unique component of the state's iconic rural and bucolic landscape. While still considered obscure by most standards, witch windows have experienced a revival in interest in contemporary times as social media has spread awareness of the phenomenon.