The Australian Institute of Architects on Wednesday called on the environment minister Sussan Ley to intervene and block the project, as it said it violated heritage protections.

A spokesman for Ms Ley said while the project was under active consideration it was not appropriate to comment on the outcome.

"A thorough assessment, including consideration of all submissions, in accordance with the requirements of the [legislation] will be undertaken," he said.

The Institute of Architects highlighted the proposed demolition and replacement of the award-winning Anzac Hall as the most egregious element of the project in terms of heritage issues.

However, a spokesman for the war memorial said consideration was focused on the overall heritage impact of the entire proposal, as the legislation dictates, rather than individual elements.

Former architects institute national president, and its designated spokeswoman for the campaign to save Anzac Hall, Clare Cousins said allowing the redevelopment to progress in its current form would set a dangerous precedent.

The memorial, as one of the nation's most significant cultural sites, should meet the highest standards in such matters, she said. If it was allowed to circumvent heritage protections then the same could happen at other important sites such as the Opera House or Parliament House.

"All of the heritage advice has been consistent in finding that the demolition of Anzac Hall will unequivocally have a significant negative impact on the [memorial's] heritage value," Ms Cousins said.

"The strength and value of Australia's legislated environmental and heritage protections would be undermined if such a violation of the Heritage Management Plan for this iconic site were permitted to proceed."

Ms Cousins said the submission from the Australian Heritage Council, the government's principal advisor on heritage matters, was particularly compelling as it said the council could not support the project for its "serious impact on the listed heritage values of the site".

However, earlier this month memorial director Matt Anderson defended the memorial's stance on heritage and said that due to the consultation process, more than 50 changes or updates had been made to the project's documents.

"The memorial's heritage assessment documentation demonstrates the proposed development provides the best balance of heritage outcomes for the past, present and future of the Memorial as the centre of national commemoration," Mr Anderson said.

"The changes are supported by more than 35 commitments to ensure that we meet the expectations of the Australian community in relation to heritage protection and conservation, environmental management, and gallery content development."

In documents within the heritage assessment, the memorial argues Anzac Hall is no longer fit for purpose and that it is considered a standalone building which gains its heritage from the items housed within it and the stories they tell.

It says the removal of the current hall will not damage the parliamentary vista of the memorial or impact on key heritage aspects of visiting the site, such as the ceremonial entrance.

While the memorial admits there were plans which maintained the current Anzac Hall, these did not fulfill other requirements of the project and were therefore not chosen.

The institute of architects has previously argued architects were hamstrung by the memorial's insistence that Anzac Hall must be destroyed and replaced.

Ms Cousins also echoed concerns raised within an auditor-general report that the current system of environmental and heritage assessment was failing.

She said it seemed the war memorial's engagement with the Environment Department during this process appeared to presuppose approval to demolish Anzac Hall would be granted.