The Energy Star® program is designed to raise consumer awareness of energy saving products. The program started with office and household products and has been extended to windows and homes.

The Energy Star® Window program recognizes that different climates have different window requirements. For Northern climates, the U-factor is critical due to the large demand for heating.

In the Southern states where the air conditioning load is largest, a low SHGC rating is required to qualify for an Energy Star® label. Low solar heat gain low E glass is necessary to protect against solar heat gain and to qualify for an Energy Star® label in Texas.