Celebrity designer Kevin McCloud has signed a petition to save Anzac Hall, part of the Australian War Memorial pegged for destruction less than two decades after its construction.
The Grand Designs star has put his name behind a campaign to prevent the demolition of the hall which would take place as part of the war memorial's $500 million expansion.
Acknowledging Canberra's design was at a juncture during his visit to the capital in February, Mr McCloud's advice was "not to mess with it", referring to the capital's heritage buildings.
"I'm anti-knocking things down just as a point of principle," Mr McCloud said.
"I think the reason we knock things down is because it's easier to knock things down and less imaginative to knock them down and just lazier to knock them down, just to replace them with something new and shiny and bling."
Mr McCloud said we were heading to "hell in a handcart" if we were to demolish the Anzac buildings.
"Unless we know where we've been and understand what our culture is we don't know where we're going," he said.
Mr McCloud reaffirmed his support for Anzac Hall in a tweet this week.
"Great architecture is a cultural asset, not a disposable asset," he wrote.
The Australian Institute of Architects petition to save Anzac Hall had also received backing from Grand Designs Australia host Peter Maddison.
Mr Maddison said the decision to demolish Anzac Hall had come from a poor competition process with a lack of transparency.
"We get great joy from visiting this building every time we're in Canberra, not only because of the content of the the AWM but the way the existing addition adds to the experience," Mr Maddison said.
"This marvellous award-winning and understated work by Denton Corker Marshall Architects should have protection."
The online petition had received almost 2000 signatures from people determined to preserve Anzac Hall, which was located at the rear of the main building.
Built 17 years ago at a cost of $11.3 million to taxpayers, the hall's demolition became more likely last week after Environment Minister Sussan Ley announced her backing of the war memorial's expansion.
There were 29 conditions the expansion would need to meet in order to "minimise and mitigate" the heritage impact on the site. Once that happened, it was expected the proposal would get the minister's final tick.
Australian Institute of Architects ACT president Clare Cousins said they were appalled the highly-awarded building had been deemed disposable.
"We understand the war memorial needs to expand. But seriously, why does the war memorial need to demolish this fit-for-purpose, award-winning building which cost Australian taxpayers $11.3 million to build and is less than 20 years old?" a statement from the institute said.
"Surely there were other more sustainable options for expansion which don't involve demolition and building from new?"
Ms Cousins wrote to Ms Ley last month on behalf of the institute, addressing their concerns over the process.
A spokesperson for the institute said her response, seen by the Canberra Times, failed to address their concerns.
"There has never been any clear, transparent and genuine public or stakeholder consultation about the proposal to demolish Anzac Hall," Ms Cousins wrote.
"On the contrary, the demolition of Anzac Hall has consistently been presented as non-negotiable since the announcement of the redevelopment."