The secondary glazing has created a large big difference in blocking out noise from exterior as well as installation was extremely swift only having an hour or so or two. Entirely recommend to any person needing secondary glazing. Unwanted noise may be accountable for sleep loss and lack of focus. https://knoxtwrsh.ageeksblog.com/26430602/acoustic-window-upgrades-in-chelsea-things-to-know-before-you-buy