The 50-year-old space-age office buildings, joined with curved tube-like walkways, were once slated for sale by the ACT government.

But some staff are now back there, and the government has called tenders for the refurbishment and fit-out of the third floor.

A spokesperson said once finished, the offices would be able to accommodate about 200 staff, consultants and contractors with the Major Projects team, which is leading the new hospital building, the shift of the Canberra Institute of Technology from Reid to Woden, and second stage of light rail.

The buildings, heritage listed in 2008, were designed by John Andrews, who was chosen for his design of the Cameron Offices in Belconnen. The Cameron Offices are described as late 20^th century "brutalist" style; the Callam Offices as "structuralist" style. Both have their concrete structural elements on the outside.

Andrews designed the Woden offices to sit above the floodplain, their floors suspended from above, after a flood that killed seven young people in January 1971.

The three pods were to form part of a group of 26 three-storey hexagonal buildings to accommodate 6000 public servants. But the project fell victim to federal funding cuts and was scrapped before the National Capital Development Commission revived a small part of it in 1977, building three pods to house the Woden TAFE.

Andrews, interviewed in 2012, hit out at what became of his plans, saying "they only built three of the bloody things and turned it into a TAFE; it was going to be a major office complex".

In 2011, then ACT head of land and property David Dawes blamed the dilapidated state of ACT office buildings for public servants moving to the federal bureaucracy, and said the government had valuation advice showing it could make $100 million from selling the Callam Offices, along with Macarthur House and Dame Patty Menzies House. The latter two have now been sold.

In 2012, the government announced plans to move Shared Services staff from the Callam Offices to a new building in Gungahlin, with then deputy chief minister Andrew Barr describing the Callam Offices as rundown.

In 2015, the ACT government announced plans to bring all ACT Health staff under one roof in Woden, including staff who were then at the Callam Offices.

In 2016, it commissioned a study to use the Callam offices and surrounding land for a new community hub. It is unclear what became of that plan.

The heritage listing says they have suffered from ad hoc changes over the years, such as security doors, the concealment of the exposed concrete floor structures, and partioning of work areas. Some of the work was ill-considered but it could be easily removed, the listing said.

The government has delayed the tram route to Woden, instead pushing ahead with a small leg that finishes on Commonwealth Avenue before the bridge. But when and if the line does get to Woden, it will travel down Callam Street, past the Callam Offices site.

Woden Community Council president Fiona Carrick welcomed the new fit-out, saying Woden needed Class A office stock.

"To make Woden a destination that people want to go to, we call on the ACT government to develop, with the community, a transport and land use plan for the town centre," she said.

Tenders for the fit-out project close on February 4.