@Thom *********
Except as a non thai, you 'buy' a max 30 year lease, effectively paying advance rent 360×12.
Service charges in addition mean you do not have a choice of dealing with the freehold 'landlord' or their representative.
Even if you get a contract for 'renewable' lease, these contracts have recently been found to be unenforceable by Thai courts.
51% Thai companies set up to circumnavigate the rules are also under very close scrutiny by authorities, some closed and enforced sale of assets.