What is Energy-efficient Glazing?

Energy-efficient glazing is the term used to describe the double glazing or triple glazing use in modern windows in homes. Unlike the original single glazing or old double glazing, energy-efficent glazing incorporates coated (low-emissivity) glass to prevent heat escaping through the windows. This makes the windows highly thermally insulating hence improving the energy efficiency of your home and helping to save money on your heating bills.

Low-emissivity glass (or low-e glass as it is commonly referred to) is a type of energy-efficient glass designed to prevent heat escaping through your windows to the cold outdoors. Low-e glass such as Pilkington K Glass™ has an invisible coating which dramatically reduces heat transfer and reflects interior heat back into your room.

Unfortunately, many older double glazed units do not contain low-emissivity glass and are therefore not energy-efficient. By replacing your existing window glass with low-e glazing, you can improve the energy efficiency of your home, reduce your monthly bills and decrease the size of your carbon footprint. Pilkington low-e glazing units can make your home more than twice as energy-efficient in comparison to older double glazing with no low-e coating.


Low-e glass is essential for rooms or buildings with a high proportion of windows or glass doors, such as conservatories and sun rooms. The use of low-e glazing helps to retain heat even in winter, allowing you to comfortably use these rooms for more months of the year. Low-e glass is also recommended for north or east facing windows, where a larger proportion of heat loss would be expected. For south and west facing glazing where overheating can become a problem in the summer months, your installer may recommend the use of solar control glass such as Pilkington Activ SunShade™.