The link at
https://propertyupdate.com.au/13-5-million-spare-bedrooms-in-australia/suggests that about four out of five households in Australians have one or more spare bedrooms.
When I was a young man living in South Africa, it was common for widows and some other owners of dwellings to have a tenant, usually a young person who has moved out of the parental home – usually to work or study in a location where their parents did not live. Also, elderly widows often lived as tenants with fellow widows. Currently in Australia, it is rare for households to have tenants – the householder would probably lose pension money and other state-given benefits if they had a paying tenant, and officialdom knew about it.
Also, if a person earns more that he or she can reasonably spend, and millions of Australians are in that position, they are discouraged by high marginal taxation to invest surplus money in profitable ways, so they hurl it at their houses with the affect of having multiple bathrooms, huge living areas, playrooms, studies, large decks, patios etc. When the owners get older, and their children have grown up, the owners are reluctant to sell, because that attracts a rapacious sales tax.
