The pink line below is the cumulative population increase divided by the cumulative no. of dwellings built in Australia since 1981.
Note there have been enough dwellings built to house 1.65 persons each.
Currently Australia's median household size is 2.6.
Does this fact support a lack of housing?
Only if there's a dramatic increase in the no. of 1 person households, and a moderate increase in the no. of 2 person households.
If there's more demand for one person households, that would explain much of the affordability crisis, as one wage doesn't service a big mortgage.
If there is a shortage, I'd argue a significant part of it is being caused by the asset rich cash poor aged, who traditionally move into retirement accommodation. Unfortunately, there's not enough 'affordable' retirement accommodation being built, so we have lots of single aged people occupying family sized homes. This trend will get worse as the demographic baby boomer bulge gets older.
govt regulation of retirement accommodation features heavily in its excessive cost to a significant % of the population.