[Closed] Double glazing advice wtd, any window fitters on here?

My dad is a window fitter and we have sash windows. We ended up getting secondary glazing recently so that we could keep the original sash windows.

The secondary units are much better than they used to be and it has made a massive difference to the warmth and condensation in the house. I think it was about 6 times cheaper than new double glazed sash windows. Even at cost that was a bit steep for me.

Yeah, we cant afford double glazed sash so it will be standard casement for us. Did think about secondary but as the the windows need a total refurb decided on replacement.