As south-east Queensland prepares to welcome almost 2 million new residents in the next 20 years, the region's lot sizes continue to shrink.

But the state government has insisted there is still enough space to grow.

The average Brisbane lot size shrank by 18.4 per cent in the past seven years, from 500 square metres in 2012 down to 408 in 2019.

Brisbane is squeezing into smaller lots as population swells. Credit:iStock

The reduction comes as more south-east Queenslanders move into high-rise buildings.