Low-e glass (low-emissivity glass) is a type of glass that has a special coating designed to reduce the amount of heat that is transferred through the glass. This coating is made up of microscopically thin layers of metal or metal oxide that are applied to the surface of the glass. The coating reflects heat back into the room while allowing light to pass through, helping to keep the interior of a building cool in hot weather and warm in cold weather.

Low-e glass is commonly used in windows, doors, and skylights to improve energy efficiency and reduce the amount of energy needed to heat and cool a building. By reducing the amount of heat that is lost through windows, low-e glass can help to lower energy bills and reduce greenhouse gas emissions.