It all seems to be an ongoing hook to hang the poor and (deliberately) under-educated peasants on. Thailand is the only country I've heard about where banks will lend you the money to buy a house as long as you first lodge the equivalent amount of money with them. Then they will use it to buy the house, charge you interest on the loan, and then allow you to pay in monthly instalments.
And before I get hammered - I know that's simplified and not (quite) accurate - but, in essence, it's what it amounts to . . . unless you can find a farang to act as guarantor . . . but, fortunately, I've never had much luck with that.