We're going to be doing this soon, when we subdivide our block. Here's some of the main points I understood -

*You don't have to make mortgage payments AT ALL for the first 12 months - on the bridging loan - but when you're calculating how much you need to borrow, it'll be cost of property + stamp duty + 12 months repayments.

So, that gives you 12 months to sell your house. Once the house is sold, the money pays off the original mortgage, with any surplus going into the bridging loan, which then automatically becomes a normal mortgage.

Does that make sense?