ENERGY STAR® Windows & Doors
As an ENERGY STAR® partner, Ply Gem® Windows & Doors is committed to meeting the strict criteria of the U.S. Environmental Protection Agency to help consumers conserve energy, reduce heating and cooling costs and protect the environment. When you purchase Ply Gem windows and doors that meet ENERGY STAR guidelines, you can be confident they will deliver superior energy efficiency and comfort for where you live.
Window configurations (frame, sash and glazing assembly) must meet a specific government U-Factor determined by regional climate conditions. Much like the more familiar R-Factor for walls, roofs and insulation, a U-Factor is used to express the insulation value of a window, however, conversely to R-Factors, the lower the U-Factor, the better the insulation value. Be sure to check the ENERGY STAR requirements in your specific climate area.