Which component of a window is referred to as the vertical framework that holds the panes of glass?

The vertical framework that holds the panes of glass in a window is referred to as the stile. Stiles are the upright members of the window frame and are critical for providing structural integrity. They create the outer edges of the window unit and support adjoining components, including the glazing and any horizontal members.

While the sash refers to the entire framework that holds the glass panes, it is composed of multiple parts, including stiles. Muntins are the thin strips of material that divide panes of glass within a window sash, often adding decorative elements to the design but do not serve as the main vertical framework. The sill is the horizontal component located at the bottom of the window frame, designed to channel water away and provide a stable base for the window.

Understanding the function of each component helps in recognizing their roles in window construction and design, ensuring clarity in architectural terminology.