Low-emissivity (Low-E) coatings are transparent metallic layers, thinner than human hair, applied to the surfaces of glass. Windows with low-e coatings are similar to tinted glass because they can block solar rays, keeping the temperature in your home more consistent. This coating prevents heat from entering buildings during the summer months and escaping from them during the winter. Low-e coatings reduce the energy loss associated with windows by as much as 40%, improve occupant comfort, and reduce damage to interior surfaces, such as rugs and furniture, from UV light. Once a novelty, low-e technology is now a market standard.
Window manufacturers use different types of low-e coatings in different climates, and the Window Selection Tool will find the right versions for your home. Low-e coatings can be tailored to specific climates. In cold climates, they block more heat from escaping a house, and in hot climates, they block heat from entering it. In moderate climates, low-e coatings balance heat blocking and heat retention.
The information on this page is used with permission from Lawrence Berkeley National Laboratory (LBNL). Download a factsheet on Low-e coatings from LBNL here.