Is it permissible to purchase an apartment if the bank pays the owner directly and stipulates interest in case of late payment, knowing that the buyer will adhere to the installment payment schedule and will not be charged interest?

It is not permissible to conclude the contract in the aforementioned manner due to the condition of usury (riba) embedded within it for delayed payment. A contract that includes and affirms the principle of usury is impermissible to conclude or complete. Rather, it must be annulled and one must repent from it if it has already taken place.