1. Frame provides structure.
2. Cladding protects the exterior of a wood or composite window and is made of vinyl, aluminum, or fiberglass, eliminating painting.
3. Sash is the moving part of the window; it can be tilted in for easy cleaning.
4. Insulated glass Double-glazed windows have a sealed space between two panes of glass filled with air or another gas that insulates better than air. Argon gas is standard on many windows, but the energy savings won’t justify paying extra for it.
5. Low-E coating is transparent and improves the efficiency of the glass by reflecting heat yet letting light in. The coating is applied to the outside of glass in warmer climates to reflect the sun’s heat out; in colder areas, it’s applied to the inside glass to keep heat in.
6. Grilles are decorative and are available in different patterns to match architectural styles.