How does this sort of loan work?
Here in Australia you borrow from the bank an amount of money that covers the cost of the house (minus any deposit you have up front) - the contract between you and the bank is that amount of money. If you can't pay the bank seeks to recover the remainder of that loaned money through such things as sale of assets (the house is first of course), re-arranged payment plan, or seeking out the person that guaranteed your loan if the bank thought the risk was too high and asked for a guarantor. The loan is purely over money which the borrower is obliged to repay.
I don't see how walking away form a loan and a house can legally work? Is the agreement different to a loan of money?