Huge real estate boom fizzled at the end of '09 / early 2010.
DANGER WILL ROBINSON! A property boom has wrecked several countries. Australia could be hit by that.
2. New buildings are unoccupied, sometimes for months.
A more useful measure is rental vacancy rates. The Australian average is 2.3%, which is pretty close to "none" in practical terms.
According to the following Melbourne has a 5.9% vacancy rate. They use water usage data from the water companies for their analysis. (<50L/day = vacant property)
http://www.earthsharing.org.au/wp-content/uploads/Philip_Soo...
REIV vacancy rate is (unleased property on the books) / (property on the books). It's always going to be an under-estimate of true vacancy due to properties that are empty full time and those that are privately managed and temporarily vacant.
> While dwellings are vacant for a number of reasons they are primarily associated with holiday areas
As someone who does live in the inner-city of Sydney and pay $3100USD/month for a shoebox. I would be incredulous if there were a large amount of vacancies beyond normal turnover.
There are usually bidding wars for property sales (most inner-city properties are sold by auction) and dozens of applications for rentals.
[ http://blog.id.com.au/2012/australian-census-2011/the-where-... ]
And there is certainly urban decay all over the city I live in (Perth).
Also, building codes are local government, aren't they? So it depends on what council you are in. And I've certainly heard some bad stories.