Please check out the new smoke alarm legislation details for yourself.
https://www.qfes.qld.gov.au/community-safety/smokealarms/Pages/default.aspx

From 1 January 2022 

For dwellings being leased, re-leased or sold, smoke alarms will need to be:

•     interconnected photoelectric smoke alarms and

•     hard-wired 240-volt or wirelessly connected 10-year lithium battery smoke alarms and

•     additionally the smoke alarms are required to be fitted in every bedroom as well as in the hallways of homes and on each storey.