Curly Black Haired Girl At The Window

Modern double-pane and triple-pane windows often include one or more low-e coatings to reduce the window's U-factor. In general, soft-coat low-e coatings tend to result in a lower solar heat gain coefficient (SHGC) than hard-coat low-coatings.
Modern windows are usually glazed with one large sheet of glass per sash, while windows in the past were glazed with multiple panes separated by "glazing bars", or "muntins", due to the unavailability of large sheets of glass. Today, glazing bars tend to be decorative, separating windows into small panes of glass even though larger panes of glass are available, generally in a pattern dictated by the architectural style at use. Glazing bars are typically wooden, but occasionally lead glazing bars soldered in place are used for more intricate glazing patterns.