Window Glossary

The part of the window which contains glass.

The ratio of the solar heat that is transferred through a glazing material relative to the solar heat transferred though 1/8” clear glass. The lower the number the more efficient the window is at reducing solar heat gains.

The horizontal bottom section of the main frame. Sill Extension: An extrusion that is attached to the bottom of the window to cover the gap between the sill and the rough opening.

A window in which one sash slides vertically and the other sash is fixed.

A glass with a thickness of approximately 3/32”

A window in which the sash move horizontally sliders are available in a 2-3 lite configuration, with the 3 lite having operable end vents

The sill of a window that has a downward slope to the outside.

The percentage of heat gained from both direct sunlight and absorbed heat. The smaller the number, the greater the ability to reduce solar heat gain.

Material placed between two or more pieces of glass, and prevent sealant distortion.

The vertical section of the sash.