There have been some sales of property in Bitcoin during the last market top, I'd suggest getting in touch with those persons involved with the sale. I don't believe there is a platform yet so you would be looking for someone to deal in BTC rathet than AUD and you want that person to have the house you want.
Couldn't you exchange for AUD then make a payment for the property. I'm not sure how this will incur capital gains on your BTC?
Hmm you have a great query that im interested in.