Please share all your double glazing wisdom! I’ve had a well known national company beginning with E round who claim theirs is the best, and the quote is pretty steep. Thing is, my parents have some of their windows, they’re over 25 years old and as good as the day they were put in. Not a single seal has gone, no condensation, opening and locking mechanisms are smooth and functional. Compared with the windows we need to replace, which are younger and absolute shit, it looks like above-mentioned company isn’t such a bad idea. What other options are there that last well? This is our forever house and I want sash windows but open to upvc sash. Recommendations please.