Residential and commercial buildings account for more than 40 percent of the nation’s total energy demand and 70 percent of electricity use, resulting in an annual national energy bill totaling more than $380 billion.^1,2 The United States Department of Energy (DOE) Building Technologies Office (BTO) is working in partnership with industry, academia, national laboratories, and other stakeholders to develop innovative, cost-effective, energy-saving technologies that could lead to a significant reduction in building energy use and enable sophisticated interactions between buildings and the electric grid. BTO’s goal is to reduce aggregate building energy use intensity by 45 percent by 2030, relative to 2010 energy-efficient technologies. The rapid development of next-generation building technologies, such as windows, are vital to advancing building systems and components that are cost-competitive in the market, meeting BTO’s building energy use reduction goals, and leading to the creation of new business and industries.

Windows are our connections to the outdoors and their thermal and optical performance directly impacts occupant comfort and building energy consumption. Next-generation window technologies can substantially reduce heat transfer compared to typical double-pane, low-E insulating glazing units (IGUs), improving occupant comfort and decreasing the need for heating and cooling in the perimeter zone. The development of thin glass (<1 mm) for electronic displays has enabled the creation of “thin-triple” IGUs, which incorporate a thin glass center lite along with low-cost krypton into a double-pane IGU form factor, surpassing triple-pane IGU performance but with substantially reduced weight and thickness.