Australia has some of the biggest houses in the world

It's often said that Australia builds some of the largest houses in the world.  In the second half of the twentieth century the growth of suburbs dominated by separate houses on large blocks has contributed to urban sprawl.  In many ways it's ironic that although contemporary planning policies seek to address these issues eg through smaller block sizes on the urban fringe and increased densities in established areas, house sizes remain large.  What data illustrates these trends?