Windows are a critical element of any building, and inefficient ones can negatively impact a building’s comfort, energy bills, and carbon footprint. In a new report, Pathway to Zero Energy Windows: Advancing Technologies and Market Adoption, the Building Technologies Office (BTO) outlines multiple avenues for technology development, deployment, and adoption to increase the impact that high-performance windows can have on decarbonizing buildings.

Currently, windows are responsible for 8.6% of energy use in buildings, and they influence end uses that make up about 43% of building end use. However, by improving the performance of windows, U.S. annual energy use could reduce by 1.7%, and CO2 emissions could fall by 1.9% in 2050. Realizing these energy-efficiency gains would be instrumental to achieving carbon reduction goals outlined by the Biden Administration.

High-performance windows utilize novel technology packages and systems like high-performance frames, daylighting, highly insulating window units, advanced glazing packages, secondary glazing, higher performing inert gas fills, dynamic window facades, and improved control methods to improve energy-efficiency performance and user satisfaction. Improving the performance of windows can do more than reduce air leakage. By optimizing the influence windows have on a building’s thermal energy demands – minimizing sunlight on hot days and maximizing it on cold ones –the size of a building’s HVAC equipment could be smaller, easing the transition to energy-efficient heat pumps.

The Pathway to Zero Energy Windows: Advancing Technologies and Market Adoption report outlines the opportunities and challenges of these existing technologies as well as guidance into future window technologies. But once a technology is developed, it needs to be installed for its energy benefits to be realized. As such, this report also provides guidance on window technology integration, market transformation, and implementation.

“Inefficient windows are a huge energy savings opportunity,” said Marc Lafrance, technology manager of the Windows portfolio at BTO. “The widespread adoption of cutting-edge novel window technologies can keep energy use and costs low while ensuring our comfort as well. We can’t reach that goal without a clear roadmap of how to get there.”

The successful research, development, market entry, and widespread adoption of novel and advanced window technologies requires sustained, long-term, and high-risk research investments. By outlining this roadmap for window technologies, BTO pushes the envelope on achieving a decarbonized building sector.

Read the report