A single main advantage of secondary glazing is it retains the character and aesthetic of the initial windows. This is especially critical for heritage and time period Homes. Decreased U-Benefit:The U-value measures the rate of heat transfer through a window. Double glazed windows have decreased U-values in comparison with https://holdennbmxi.tinyblogging.com/new-step-by-step-map-for-london-secondary-glazing-78310746