On this certain example The brand new double glazed sash windows along with the retrofitting both of those benefitted from the 4-8-four Argon crammed, low-E, toughened device, as well as a white spacer bar. The one difference I suppose glazing wise was the sandblast glazing in the original sash. It https://riverehhfe.estate-blog.com/26106972/detailed-notes-on-condensation-resistant-glazing-in-wc2e