Defence heads decided against moving the swelling Australian Cyber Security Centre from the new ASIO building to the spy agency's former headquarters, a parliamentary committee has heard.
The Joint Standing Committee on Public Works scrutinised department representatives on the $38.8 million decision to move the cyber security centre to Brindabella Business Park, just two years after the organisation moved into the custom-built Ben Chifley Building.
The representatives revealed they considered moving the centre to ASIO's old headquarters in the nearby Russell Offices precinct, but a cost-benefit analysis found the building works alone would cost $22 million more than the total Brindabella Business Park proposal.
Sites at Majura Park and Fairbairn were also rejected for the move, with Brindabella chosen due to the number of Defence facilities already based at the precinct.
The move to 14 and 16 Brindabella Circuit was proposed to accommodate an extra 400 employees and cater for staff unable to access the security clearance required to work in the Ben Chifley Building.
The proposal, drafted less than two years after the ACSC moved into the $700 million spy headquarters skirting Parkes Way in late 2014, was a response to the federal government's expansion of cyber security last year.
The committee heard the centre's current residence, inside one of the most secure buildings in Canberra, hindered collaboration with partner agencies and the public.
It heard that barrier also discouraged applicants who were unwilling to wait for the long vetting process when they could access employment elsewhere for their "high demand" skills.
The new premises would be fitted out with different tiers of security restrictions to allow better consultation with academics, businesses and other government departments.
The centre has room for 300 staff at the Ben Chifley Building, space that would be filled by ASIO if the parliament approved the ACSC's move to Brindabella Business Park, the committee heard.
When questioned about the decision to move two years after the centre shifted to the Ben Chifley building, Defence officials said they could "not have foreseen" the government's 2016 decision to expand the organisation under its Cyber Security Strategy.
About 700 staff are expected to work at the cyber security centre by 2020, including the current 300 allocated jobs, 200 new positions and 100 each from partner agencies, academics and interns or graduates.
The Brindabella Circuit buildings, which are currently unoccupied but used to house the Department of Employment and Industrial Relations, will be examined for security risks.
Depending on approval from parliament, Defence has planned to begin fitting out the Brindabella Circuit buildings as early as next month, with staff to begin moving in by June.
Most of the existing staff would be moved over by the end of the year.