Thermal Performance

The average heat loss through replacement windows can range from 50 watts per square meter to as little as 13 watts per square meter. For a three bed house, this can amount to a huge difference in annual energy use. To maintain a constant comfortable room temperature of 21 centigrade across the year, the difference could be 11,400 KW hours compared to 3,150 KW hours per annum. In financial terms, this could be a difference of over £500 a year.