A leading urban planner has accused planners of destroying the great Australian dream and urged the government to drive a renewed focus on middle Australia by targeting development on the outskirts of Sydney.

Decentralising growth across Sydney would drive down housing prices, improve the cost of living for Aussie battlers and boost environmental outcomes, America’s “uber-geographer”, Joel Kotkin told the sixth annual Bradfield Oration.

Investing in infrastructure and jobs in the outer suburbs of Sydney will dramatically change outcomes for disappearing “middle Australia,” he said, arguing that the great Australian dream had been destroyed by the centralisation of growth.

media_camera Joel Kotkin pictured speaking at The Daily Telegraph's Bradfield Oration event at Luna Park Sydney. Picture: Damian Shaw

The powerful comments come after editor Ben English told the audience of more than 200 that Sydney’s future depended on city planners coming together with a co-ordinated vision for the future of the city.

“Sydney’s an amazing place, no doubt, but only if we keep it that way. The indictment however is a bit harder to defend. And the charge is this: how is it that we, members of the collective brains trust of this city, have managed so few world-class feats of engineering and development in the past century?

“I don’t think it’s because we here in Sydney lack vision … I’d put it to you that the problem is we have too many competing visions.”

media_camera Ben English editor of The Daily Telegraph speaking at The Daily Telegraph's Bradfield Oration event at Luna Park Sydney. Picture: Damian Shaw

With home ownership sitting at less than 45 per cent and families increasingly choosing not to have children, Mr Kotkin urged governments to plan the city’s future not merely for apartment dwellers, but for the forgotten suburbs.

“We are creating a situation where it’s very difficult for people to start a family and have kids and that’s not the future I want.

“All these people came for the great Australian dream and they don’t get it. I don’t want to know what the political and social ramifications of that will be.”

media_camera Guests at The Daily Telegraph's Bradfield Oration event at Luna Park Sydney. Picture: Damian Shaw

With the vast majority of population growth occurring in the outer parts of the city, Dr Kotkin argued that transport infrastructure into the city for those living in outer parts of the state needs to dramatically improve along with the infrastructure and jobs available in the outskirts of the city.

“Australia has the greatest egalitarian spirit and that’s starting to fade and that’s a great tragedy,” he said. “The city is going wherever [middle Australia] goes. The fate of Sydney is not the fate of its inner core. It’s about wherever the citizens go.”

After Mr Kotkin's speech, a panel of experts joined the call for government action to boost opportunity for middle Australia.

media_camera Bradfield Board chair, Tony Shepherd, Australian Museum CEO Kim McKay and former Victorian premier Jeff Kennett discuss the future of sydney with panel host Sharri Markson.

In a panel led by the Sharri Markson, former Victorian premier Jeff Kennett and founder of Beyond Blue said the housing market was at risk of tipping over if more attention wasn’t paid to the Aussie battler.

“There is a real issue at the moment with low interest rates and very fat wages. The rich are getting richer. And if it continues much longer [the market is] at risk of explosion,” Mr Kennett said.

Independent chair of the Bradfield Board, Antony Shepherd, argued that unlocking vacant blocks of land in the outer suburbs was the panacea to the decline of middle Australia.

“We’re not having enough concentration on getting a supply and demand balance.”

Director and CEO of the Australian Museum Kim McKay urged bureaucrats to step up, saying

housing was way out of reach for the average Australian.

“Berejiklian and her team are trying to cut the red tape but they need to do more. There are three levels of bureaucracy in Australia and I don’t think they’re going to disappear any time soon.”

Investment in cultural infrastructure in the outer ring of Sydney would also drive growth in these suburbs, Ms McKay said.

“I’d love to see a network of cultural infracture in the suburbs. A vibrant suburban environment for Sydney.”

The Greater Sydney Commission’s idea of a metropolis of three cities — the eastern harbour, central river and Western Parkland — would also help promote opportunity for all residents, My Shepherd said.