My previous house was a Victorian semi that had cavity walls. I phoned up about a green grant to get it done (as people two doors down had) and they wouldn’t believe me until they checked Google Earth. Had it surveyed and it would have needed a lot of preparation work to get into a condition that it could have been insulated. Ended moving and I am unsure what the new owners have done on that front - not flash enough to make their Instagram account about renovating the house which I have been advised not to read as they are horrible people with bad taste. Although I get the gist as it often gets commented on at parties, especially as a friend’s brother-in-law did the bathrooms.