Long running restoration work at one of Canberra's historic public service office buildings have been extended by more than a year.
Repairs to the facade of the John Gorton Building had been due for completion by May this year, but Department of Finance officials told a Senate estimates committee this week the timeline has been extended to July 2018.
![Restoration of the John Gorton building has cost $17.3 million so far.](http://web.archive.org./web/20170722154519im_/https://www.fairfaxstatic.com.au/content/dam/images/1/2/2/l/m/u/image.related.articleLeadwide.620x349.gxft9h.png/1500627760051.jpg)
Emergency remediation works were ordered for the building, built between 1927 and the early 1950s, when pieces of the sandstone facade started falling to the ground. Deemed as a potentially "catastrophic" risk to staff and the public, protective fencing and hoarding was installed in late 2013.
Previously known as the Administrative Building and at the heart of the parliamentary triangle, the heritage listed structure has seen $17.3 million worth of restoration work so far, including securing crumbling stone and removal of asbestos materials.
![Stonework had been at risk of falling from the facade.](http://web.archive.org./web/20170722154519im_/https://www.fairfaxstatic.com.au/content/dam/images/1/2/2/l/m/a/image.related.articleLeadwide.620x349.gxft9h.png/1500627760051.jpg)
The safety measures had been expected to remain in place for more than three years and coincided with the Department of Finance leaving the building to move to the $376 million 1 Canberra Avenue development.
An Environment Department report highlighted risks from falling sandstone panels and lead capping described as "critical", while further inspections found the stone work and lead had been showing signs of accelerated deterioration.
Of the building's 100 wall surfaces, fallen material was found at the base of 16. An estimated 4 per cent of the 24,000 panels needed to be replaced while 10 per cent could be repaired. Pointing between the panels were found to contains deadly asbestos materials.
A six-metre exclusion zone was established around the building's 14,000 square metre footprint.
![Protective barriers have been in place since 2013.](http://web.archive.org./web/20170722154519im_/https://www.fairfaxstatic.com.au/content/dam/images/1/2/2/l/n/p/image.related.articleLeadwide.620x349.gxft9h.png/1500627760051.jpg)
A range of public servants, including Department of Environment and Energy employees, have continued to work inside during the restoration.
"The current scheduled completion date for the project to repair the facade of the John Gorton Building is July 2018, extended from May 2017," officials told the Finance and Public Administration committee.
"This is due to far more extensive stone repairs required than originally scoped which only became evident as stone work was removed for repair, and reflecting schedule delays as a result of weather events."
The cost as of April 30 has reached $17.3 million, up from $8.6 million in mid-2016.
The building resulted from the winning Academic Classical style design in a 1924 architectural competition for a major administrative building in the new national capital.
With construction delayed by the Great Depression and World War II, the building was redesigned in 1946 in the Inter-War Stripped Classical style before being completed in 1956.
Its basement was used for an underground communications hub until the mid-1990s.
In 2015, the Abbott government opened up the possibility of the building being sold, along with the nearby Treasury headquarters, the East and West Blocks and Anzac Park East and West.
Amid criticism from Labor and heritage advocates, the plan was scaled back and following changes to the National Capital Plan, the Turnbull government announced in April it would sell the ageing Anzac Park buildings along withe East Block, home to the National Archives of Australia.