Not sure on getting it right. Old houses in the UK are a nightmare in term of thermal and sound insulation (basically none). Sure, it protects your head from the rain (when it doesn’t leak). But in a discussion about consuming less energy, thery are pretty much a counter-example of what to do.
People have been doing it and usually getting it right for millenia. 38% of the UK's housing stock dates from before 1946; much more than was built in the last forty years.
And one of the few really consistent objections to older buildings is 'the architects assumed nobody would still be living in it fifty years later'...