Are government-subsidized housing loans permissible, regardless of whether the bank is usurious or not, and do they become permissible if they are through Islamic Murabaha from an institution such as the Orphan Fund Development Foundation?

If the housing loan subsidized by the state has a small interest rate and a long repayment period, then it is forbidden usury (riba). However, if it is a benevolent loan (qard hasan (definition)) with no interest, then it is permissible. Islamic Murabaha, which is when the bank buys the building materials and then sells them to you for a price higher than their cost, is permissible if conducted according to the rules of Sharia (definition).