I have been working on sash windows for over ten years and still get excited dealing with 250+ sash windows each year...
As well as dealing with windows for my customers, I carry out product testing and training for my local supplier DRAFTFIX ltd in Bury st Edmunds who sell "the UK's No 1 sash window draught proofing system"...
I believe sash windows should be saved for aesthetic, historical, ecological and financial reasons. They can be repaired and improved upon and are easy to use and maintain.