The Southern Employment Lands is a state significant area.

An area about 12 times the size of Barangaroo will be quarantined from Sydney's apartment boom, a move supporters say will ensure emerging businesses and industry are not pushed out of the inner city.

The state government and council jointly funded a 2013 report into the "strategically important" employment lands, which found most of the precinct should support a broader range of employment uses, plus housing in some areas.

The plan was supported by all but one councillor, splitting the Liberal block on council. Councillor Edward Mandla said it limited the area to "industrial commercial archaeology" rather than what should be a mixed-use precinct.

Cr Mandla estimated the area could house 100,000 people – about twice that of the 278-hectare Green Square redevelopment, which is to be the densest precinct in Australia.

The inner city precinct that is bigger than Barangaroo and almost apartment-free