This is a Request for Information (RFI) only. This RFI is not accepting applications for financial assistance. The purpose of this RFI is solely to solicit input for ARPA-E consideration to inform the possible formulation of future programs. The purpose of this Request for Information (RFI) is to solicit input for a potential ARPA-E program focused on the development of highly insulating R-10-rated glass for windows and R-50-rated walls for residential and commercial building retrofit and new construction.1 This RFI aims to identify potential participants and gather insights to inform the development of a potential funding opportunity focused on these transformative technologies. Heating and cooling of residential and commercial buildings in the United States accounted for about 12% of total national energy consumption (amounting to 12 quadrillion British thermal units) in 2022.2 Approximately 45% of this heating, ventilation, and air conditioning (HVAC) energy was used to compensate for heat transfer through the building envelope (e.g., windows, walls, doors, attic, and air leaks).2 Reducing the energy a building uses has multiple benefits beyond lower utility costs and carbon dioxide emissions. Smaller, less expensive HVAC equipment and ducting systems would increase useful interior space and reduce demands on the electrical grid. To view the RFI in its entirety, please visit https://arpa-e-foa.energy.gov.