National Archives of Australia director-general David Fricker says federal government agencies are now spending about $220 million a year storing their paper records.

"And that amount is only going to grow, as more information is created," Mr Fricker said. "Two-hundred-and-twenty-million dollars is not sustainable; it's wasteful."

The director-general and Arts Minister Simon Crean, who oversees the archives, toured the agency's Mitchell repository today, where some of the government's most important historical documents are conserved.

Mr Crean warned public servants they had until 2015 to shift to a digital archiving system, as the government would not allow paper files to be produced after that date.

The minister confessed he still preferred to read his briefs on paper.

However, he said the public service was creating a "mind-boggling" amount of documents.

"In any one year, the Commonwealth agencies, all 200 of them, generate, I'm told, 850 million pieces of paper."

To cope with the demand, the archives is in the process of expanding its two largest storage sites, Mitchell and Chester Hill in Sydney.

Plans are also under way to build another large preservation facility in Canberra.

However, Mr Fricker said the archives was pioneering techniques of digital record-keeping that would save the public millions of dollars if adopted by government agencies.

Digital records were also far easier to access and search, he said.

"In the long run, it's going to enhance all ... Australians' ability to access and make use of these records."

The federal bureaucracy's five-year IT sustainability plan, published in 2010, said the government used up an estimated 6500 tonnes of office copy paper a year.

It set a target of cutting each public servant's internal paper use from an average of 40 sheets per working day to 20 by 2015.