Which term denotes the vertical element that divides a window into units of light?

Which term denotes the vertical element that divides a window into units of light?

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

Answer: (A)

The vertical element that divides a window into units of light is called a mullion. Mullions run along the vertical axis and frame each individual pane, creating the divisions that define the window’s lighted segments. They can be structural or decorative, shaping the window’s appearance and proportions. A transom, by contrast, is the horizontal member above a window that separates it from the area above or forms an upper light, so it isn’t the vertical divider. A scroll is a decorative curved motif, and intercolumnation refers to the spacing between columns in a colonnade—neither of these describe the vertical division within a window.

The vertical element that divides a window into units of light is called a mullion. Mullions run along the vertical axis and frame each individual pane, creating the divisions that define the window’s lighted segments. They can be structural or decorative, shaping the window’s appearance and proportions. A transom, by contrast, is the horizontal member above a window that separates it from the area above or forms an upper light, so it isn’t the vertical divider. A scroll is a decorative curved motif, and intercolumnation refers to the spacing between columns in a colonnade—neither of these describe the vertical division within a window.