Kevin Rudd ventured into Sydney’s mortgage belt this morning, announcing details of the ALP's housing affordability policy in the seat of Werriwa.

Speaking from a housing estate in Ingleburn, Rudd promised to unlock up to $6 billion in Commonwealth land for housing development to help ease affordability.

"What we would require is, each year, every Commonwealth government department to come back to the minister for housing and say 'here is the surplus land we have' and to show cause why it should not be released for housing development and wider community infrastructure development."

The land would be released once a Government land audit is completed and results released.