Developers will have appetite for 60,000 new high-rise dwellings along the controversial Bankstown rail line redevelopment, or nearly 25,000 more than the community has been told will be constructed, according to a previously unreported study commissioned by the state government.
The state government maintains only about 35,000 dwellings will be built in the Sydenham-Bankstown redevelopment over two decades as 11 stations such as Dulwich Hill, Campsie and Bankstown are redeveloped into a metro project. That figure has already seen it face a backlash from a slew of local residents groups.
But a report from its own consultants suggests that developers' appetite will far exceed the government's published plans for the redevelopment.
"[Modelling] suggests 58,747 new dwellings ??? could be financially feasible to develop," a newly released study commissioned by the department from AEC Group last year found. "[And] should the strategy be implemented new planning controls could unlock surplus market capacity of nearly 40,000 dwellings."
The state's opposition said the document showed that the state government was planning to "ambush" the community with future increases in density.
"The Bankstown to Sydenham rezoning plan is just another giant property play by the Liberals," said shadow planning spokesman Michael Daley. "The developers have already started doorknocking.
"The Liberals need to trash this plan and do another one - one that identifies where the new schools, new hospitals, parks, gardens and community facilities will go, then talk about population growth."
The department of planning did not dispute the consultants' estimates, but said the document was only an initial forecast and it would ultimately control how many developments were approved and balance growth with infrastructure.
The consultants also forecast an increase in the construction of high-rise towers in the outer suburbs as residents "attitudes" adjust and become more accommodating of high-rise towers.
The study suggests that the entire 13.5-kilometre corridor has a theoretical capacity of 90,000 new dwellings.
Only two-thirds of those would be "financially feasible" to develop but the document predicts accelerating density growth in the outer suburbs as time wears on.
A map of the area affected along the Sydenham to Bankstown line. Photo: Supplied
"We expect in the near to medium term, development activity will in the main comprise of buildings under 10 storeys until such time revenue levels justifying the cost of constructing taller buildings," the document reads.
"Over time, we expect market attitudes towards higher density living in [outer stations such as Lakemba, Bankstown and Punchbowl] to align with those [closer to the city].
"This will result in ??? making it more financially attractive for developers to pursue redevelopment opportunities."
A spokeswoman for the department of planning said: "Feasibility of development is [only] one aspect considered in understanding the growth potential of an area.
"Rezoning needs to occur for the majority of development to occur. The department and [councils] can control the rate of growth."
The department has estimated Greater Sydney will need 35,000 new homes a year to meet projected population growth.
Under the plan, residential and mixed use developments will be allowed within 400 metres of the 11 major stations.