The heat lost from the windows of buildings in winter is very great. According to America statistics, buildings lose about 30% of their energy through windows. Sweden has a much larger share, about 70 percent. The statistical data of China show that it accounts for about 50%. 

The practice at home and abroad has proved that improving the thermal insulation performance of building envelope, especially improving the thermal insulation performance of windows, is the most economical and effective method to prevent the heat loss of buildings. The application of insulating glass in architecture plays a key role. Tall office buildings use silver-gray hollow glass windows that use 5494KJ per square foot per year for heating, about two-thirds less energy than single-story windows, according to America data.