windowpanes

Windowpanes are flat sheets of glass used as the transparent component of a window. The term can refer to a single pane or multiple panes within a window or building envelope.

Most contemporary windowpanes are made of glass produced by the float glass process and are installed in frames such as wood, aluminum, or vinyl. Modern windows often use insulating glazing units, consisting of two or more panes separated by a spacer and filled with inert gas to reduce heat transfer.

Glass panes can be reinforced or altered for safety and performance. Safety options include tempered glass, which breaks into small granules, and laminated glass, with a plastic interlayer that holds shards together. Coatings can reduce heat transfer or glare, including low-emissivity coatings and tinted films.

Historically, windowpanes were formed by drawing or crown glazing and posed challenges for large panes. The advent of plate glass and, later, the float glass process enabled larger, more uniform panes. In older architecture, panes were small and often leaded or muntin-divided.

Installation involves securing the pane in a window frame with glazing beads or putty, and sealing to prevent air and water infiltration. Maintenance includes inspecting for cracks and seal failures and replacing compromised panes to restore energy performance and safety.