Vertical members dividing windows into different numbers of lights are called what?

Vertical members dividing windows into different numbers of lights are called what?

• A. Mullion
• B. Transom
• C. Intercolumnation
• D. Scroll

Answer: (A)

Vertical divisions in a window are mullions. Mullions are the main vertical framing members that separate the glass into individual lights, giving the window its distinct set of panes and helping define its rhythm and proportion. If a window is divided horizontally as well, that horizontal piece is called a transom, not a mullion. Intercolumnation refers to the spacing between columns in a façade, not to window divisions, and a scroll is a decorative curved motif rather than a structural member. So the vertical divider that creates separate panes is the mullion.

Vertical divisions in a window are mullions. Mullions are the main vertical framing members that separate the glass into individual lights, giving the window its distinct set of panes and helping define its rhythm and proportion. If a window is divided horizontally as well, that horizontal piece is called a transom, not a mullion. Intercolumnation refers to the spacing between columns in a façade, not to window divisions, and a scroll is a decorative curved motif rather than a structural member. So the vertical divider that creates separate panes is the mullion.