A recent investigation by an international housing affordability think tank, has discovered Australia’s five biggest cities have 'severely unaffordable' housing markets.

In its 14th annual report, Demographia found Sydney was ranked ‘second worst’ in the world, with house prices almost 13 times higher than the median household income.

Head of CoreLogic Tim Lawless agrees that under the urban-containment policy, the boom in apartment buildings across many of the states isn’t helping with affordability.