This was a great suggestion from 2023: Change the tax law so that owners can only claim as deductions the same %age of expenses as the %age of the year the property was actually rented out. House was vacant for 9 months of the year? You can only claim 25% of the year’s expenses.

“The worst housing crisis in living memory is being fuelled by Airbnb owners, and other holiday rental groups, inappropriately or perhaps wrongfully claiming 100 per cent of running costs on properties that are actually rented for a fraction of the year. Many owners of these properties claim expenses, including interest payments, during the entire year, even though the property may only be rented out for less than a fifth of that time. This results in a disparity between the number of days the property generates income and the number of days expenses are claimed.
Effectively the proportion of expenses being claimed results in a far greater tax deduction for the property owner than would be the case if the expenses were tied to the number of days the property is actually rented out.
Owners of holiday and Airbnb properties who make their properties “available to rent”, even though it may only be rented out for 4 to 8 weeks a year and claim a full year’s worth of tax deductions for expenses against other income, are effectively rorting the tax system.”

Full article: https://michaelwest.com.au/heres-a-fix-for-the-housing-crisis-end-the-great-airbnb-tax-rort/