Comment by ghaff

It doesn't take much. A neighbor and I just had to deal with a bunch of property line confusions in the US where a property subdivision 25 years ago wasn't handled correctly. None of us really cared but it would matter in the event of an eventual sale and it cost thousands of dollars in surveyor and legal fees.

ADDED: We also had a bunch of easements and cooperative maintenance agreements that were only partially documented in the deed and mostly done via a handshake. So we got that all squared away in the expensive binder from the lawyer.