How about capital gains tax on property., page-16

One side effect of no CGT on family home. Not sure if same in Sydney, Melbourne BUT. A common theme here in Perth in the 80s and up to last 5 years. Put all your money into building the biggest house you can afford you get to live in luxury and a massive tax free gain to fund your retirement when sell. Many massive luxury houses built around Perth the Northern beachside suburbs in particular from Karrinyup to Yanchep. The problem is now manifesting and getting worse
A Owners getting old and kids moved out, so living in empty mausoleums
B Supply Supply too many big houses flooding the market
C Cash flow. Houses require maintenance and money in rates etc. yeah sure you house is exempt from assets test for pension but living on pension in a Mc Mansion is now nicknamed The starving Rich
D Ego prevents many from scaling down and living in a lesser area.
E Cannot sell a part of your house.
F The irony now is smaller houses in close to facilities are costing more than the big boxes in the burbs.

Taxing the home is not the answer to affordability. I am just pointing out human nature will always try to exploit rules sometimes it works and sometimes it is a disaster.