Is it permissible for me to transfer ownership of the house to the bank to pay the remaining portion of its price with interest, knowing that this was not part of the original agreement and I do not possess the required amount?

If the agreement to defer and installment the apartment's price has been made, then it is binding on the association and cannot be revoked. The debtor cannot be forced to take out a usurious loan. The questioner is not permitted to borrow from the bank with interest except in a case of extreme necessity.