The Abbott government is opening up the possibility of private companies buying Commonwealth buildings within the Parliamentary triangle.
Finance Minister Mathias Cormann has put the future ownership of six iconic buildings in the zone in doubt, as the government tries to balance the budget.
The sale could include the John Gorton and Treasury buildings, East and West Block and Anzac Park East and West, which are all ageing and expensive to maintain.
ACT Heritage Council chairman Duncan Marshall criticised the plan, saying East and West Block were intrinsic parts of Canberra's early heritage.
ACT Property Council executive director Catherine Carter said it was a sensible decision for the federal government to sell these ageing assets and it should consider selling many more buildings.
Senator Cormann said on Friday the government remained committed to realising the value of Commonwealth property through its divestment program.
"We are now undertaking a scoping study into the divestment options of six Commonwealth properties in Canberra," he said.
"These buildings are the John Gorton and Treasury buildings, East and West Block and Anzac Park East and West, all located in the Parliamentary Triangle.
"The scoping study will consider alternative uses for the properties, particularly noting their location, cultural and heritage significance.
"The scoping study will also consider the future ownership of these buildings, taking into account significant ongoing maintenance and refurbishment requirements.
"Following a competitive procurement process, PricewaterhouseCoopers has been appointed as commercial adviser and Ashurst has been appointed as legal adviser to assist with the scoping study.
"The advisers will provide independent advice to allow the government to make fully informed decisions on all relevant aspects of the potential divestment of these properties.
"Ownership options will be considered in the context of the 2015-16 budget. Importantly, the government has not yet made any decisions regarding the timing and structure of any potential sale."
Ms Carter said the announcement of a scoping study into the divestment options of the six Commonwealth properties had been welcomed by the Property Council of Australia.
"It is a sensible decision for the Commonwealth government to divest itself of these ageing assets," she said.
"Building management is not a core function of government and the private sector is better placed to own and manage assets on the government's behalf.
"The property industry has the expertise and experience to better manage and maintain these buildings, and to ensure the Australian taxpayer gets best bang for its buck.
"We believe a divestment strategy should extend beyond these six buildings to the entire government portfolio, with the exception being strategically important assets such as Parliament House and buildings owned by ASIO and the Department of Defence."
Mr Marshall pointed out the parliamentary triangle had been reserved for government use since Canberra was created.
"It does seem like a fairly major step to take for the Commonwealth to start allowing essentially private ownership of major buildings within the Parliamentary Triangle," he said.
"It would seem very disappointing if the Commonwealth government were to move out of central Canberra, that would seem to be contrary to the spirit of the planning of Canberra by the Griffins.
"I would've thought the actual ownership by the Commonwealth of at least some of these buildings was integral to their heritage value, particularly in the case of the oldest of these buildings, East and West Block.
"They are some of the earliest Commonwealth buildings in Canberra.
"They were the buildings that enabled the Commonwealth to really start the business of government in Canberra, they played a strong supporting role to the government and to the parliament in those very early days.
"From memory, I think the first cabinet meeting held in Canberra was held in West Block."