EVERY Australian family should be limited to just two children to curb the population explosion, controversial millionaire Dick Smith says.

He called for a China-like quota on the number of kids, warning the growing burden on our resources was like "a plague of locusts".

Likening high-rise apartments to chicken coops, the former Australian of the Year thanked property developers at an Urban Taskforce population debate in Sydney for "not lynching" him after he attacked their drive for profits and called for an end to the growth addiction.

"It's either going to be forced on us or we are going to plan to stabilise," Mr Smith said.

"I would like to see Australia stabilise at 24 to 25 million. I don't see it by force I see it by saying to parents, it's best to have two kids. I see us having an immigration intake of 70,000 per year."

Unaffordable land prices left generations of children stuck in apartments, he said.

"We descended from hunter gatherers - not from termites," Mr Smith said.

"We are putting our kids into high-rise because we are running out of land, because people want and need to live close to the city. We pay $50 million a year for free range eggs for our bloody chooks to be free range - what about our kids? I was a free range kid. I had a backyard. We are starting to lose that now, and it's only driven by the huge population increases."

Population growth had to slow to allow housing to become affordable again, he said, warning bad handling could lead to a recession.

Mr Smith called for an end to "stealing resources" from future generations.

"We have to decide - are we like locusts that breed to huge numbers and then die off? Or are we like the majority of other magnificent natural creatures in this country which have lived in balance for millions of years?" he said.

" We have to decide we're going to live in balance or breed up and die off. There are people who say we will get to 9.1 billion and one enormous catastrophe will wipe out most of the people and if that's going to happen enjoy the advantages now. That might not happen."

Mr Smith said the economic system was built on "perpetual exponential growth".

"We are completely addicted to growth. It's like the religion of capitalism but it is a false God," he said

MacroPlan economist Brian Haratsis called Mr Smith alarmist and "using scare tactics"

He said population debate in Australia had been stolen by "anti-growth people with a Green sentiment".

"We can triple the population of Australia if we want to and we wouldn't use much land. You only have to jump in a plane to Sydney and fly to Perth and what do you see? Not much."

Mr Haratsis said a population of 40 million was inevitable and that "the only choice is if we want a really big Australia of 40 million to 80 million".

Originally published as 'Limit families to two children only'