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Bay Window

A bay window is a window assembly that projects outward from the main wall of a building, forming a small alcove inside the room. It usually has a flat center window with two angled side windows.

A bow window is a related design that curves outward using four or more windows of equal width. Some bay windows extend down to the foundation and add real floor space. Others are cantilevered, hanging off the wall at sill height, and add only a window seat or shelf.

Whether a bay counts toward square footage depends on whether it adds floor at floor level and meets the usual height and finish rules. See bay windows and bump-outs in GLA.