To what extent is purchasing housing permissible in the manner described, and is it considered a manufacturing contract, given the existence of a down payment while the final cost of the dwelling, its area, and location are unknown, and the remaining amount is paid through an interest-based bank or as an intermediary, and in case of inability to pay, is the person transferred to the bank to pay the remainder with interest?

The manufacturing contract (Istisna') has conditions, including the knowledge of the manufactured item's specifications and price. Since the residential units are not known in terms of area and cost, the contract is invalid. Furthermore, it is not permissible for the bank to pay installments on behalf of an individual with interest, whether initially or upon failure to pay within the specified period. Therefore, it is not permissible to purchase a residence in the described manner, except for one who is in dire necessity.