Owning your own home

Buy, burn down windmill in 'accident', build three story eight bedroom eyesore / mansion?

Buy windmill.

Mill Hipster craft flour and bake bread.

Profit.

It's one residential property, a normal mortgage would be fine.

But a Grade I Listing is something to be taken very, very seriously. There are only a few hundred Grade I Listed buildings in most counties and 90% of them are churches and castles and shit. You can't paint a wall or replace a broken tile or put up a picture without permission. I'd go nowhere near it unless you get a kick from bureaucracy and have very deep pockets.

Insurance would be stratospheric.