Must the debts of the old owner be borne by the new owner?

Any fees owed by the original owner should not be passed on to the new owner. If the original owner refuses to settle the relevant fees, the landlord can sue.

Second-hand housing transactions do not apply for new real estate licenses, but also settle property fees and other related expenses. The general practice is that the original owner shows the settlement voucher of the property fee, water and electricity fee, heating fee and other related expenses in the current month (in fact, it is the bill for paying money), and the buyer will transfer the ownership after confirming it is correct. The landlord was really negligent this time.

What the landlord said has nothing to do with whether the house is demolished or not.