The ACT has more heritage locations deemed ''at risk'' than any state or territory, according to the National Trust.
The organisation is unhappy with Canberra's apparent willingness to maintain a heritage facade while simply gutting or demolishing the rear of significant places.
It is concerned about the level of ''internal destruction'' planned for the Law Courts Building, which is to be gutted, and accuses the ACT government of taking a cavalier attitude towards the site.
The trust says other areas at risk are the housing precincts of Ainslie, Blandfordia 5 (a section of Griffith) and Reid, where there are ''demolitions contrary to mandatory requirements … leaving only facades of listed houses, to be surrounded by rebuilds of unsympathetic character''. The organisation is also concerned about plans to infill a section of Lake Burley Griffin to make way for the Australia Forum and a possible new Canberra Stadium.
These are the areas in the ACT listed by the National Trust among Australia's 10 most at risk sites.
In Victoria they include the Argus Building in Melbourne and the Castlemaine Gaol, and in South Australia, the Royal Adelaide Hospital and the Elder Park bandstand in Adelaide.
ACT Chief Justice Terence Higgins and his judges have been lobbying for years to replace the crumbling Supreme Court building on Knowles Place in Civic with a complex capable of meeting the modern needs of the court. Two levels will be built underground for parking, along with subterranean courtrooms and a tunnel between the Supreme Court and Magistrates Court.
Attorney-General Simon Corbell has said the only parts of the 1963 Supreme Court building to remain would be its facade, columns and coat of arms. The interior would be gutted, except for timber panelling originally gifted by the states which would be re-used in some form.
Mr Corbell said last year, when announcing the project, the building was not heritage-listed but it was important to keep its design features in the new development.
Dr Peter Dowling, national heritage officer, said on Friday the National Trust was disappointed the nomination of the law courts building to the ACT heritage register had not proceeded. ''We are also extremely disappointed and deeply concerned about the level of internal destruction,'' he said.
''The National Trust has no objection for buildings to undergo substantial and functional refurbishment but at same time to completely gut the building and just leave a facade is not acceptable. There should be some more sensible way of identifying the significant elements that relate to its history and its heritage values and make a good attempt to retain some of that fabric. That doesn't seem to have happened in this case.''
Dr Dowling disputed Mr Corbell's reported statement that the building was not heritage-listed. ''What the minister didn't say was that it was once heritage-listed,'' he said.
''When the register of the national estate became defunct earlier this year, a lot of places that were on the register were not picked up by state and territory heritage lists, suddenly had no legislative protection.''
A spokesman for Mr Corbell said all appropriate steps to recognise the heritage values of the Supreme Court building had been carried out.