Record immigration in Australia: 400k will arrive this year, page-66

The thread title is a bit misleading.
Net migration is a number that relates to visa types and the amount of time people stay in Australia.
If you look at the figures it includes people have changed visa types and more people who are already here in accommodation will be staying longer.
Many of the new arrivals will be staying in student accommodation and backpacker hostels along with share housing.