I found this site whilst looking for something else and thought it might be useful for people
http://www.historic-scotland.gov.uk/windows_leaflet.pdf#search="
http://www.historic-scotland.gov.uk/windows_leaflet.pdf#search="
plumbers mate said:Mr Ventrolla is coming in Dec to do mine - I need to save up - quick!
We don't experience noticeable draughts with the windows currently, so I'm unsure as to whether this is worth the extra expense.