Parents are fighting to stop demolition of the historic facade of Mt Lawley Primary School, which was gutted by fire last month.
They say the Education Department is putting economic decisions ahead of the building's heritage value and its importance to the community.
Almost 300 people have signed a petition to the State Government and the Education Department calling on them to make a structural report public and provide detailed reasoning why the original facade cannot be saved.
The department has told the school community that many, if not all, walls were unstable and the "most cost-effective" solution was to demolish parts that were destroyed and rebuild.
A parent who helped organise the petition but did not want to be named said many parents had spent a lot of money complying with local heritage requirements when renovating their own houses.
"There is a perception that one rule applies to the Education Department and another to the local community," the parent said.
The Mt Lawley Society, which aims to preserve local heritage, said there was no compelling reason for the facade to be demolished.
Society president Bruce Wooldridge said the school was an important part of the City of Stirling's heritage protection area and scaffolding should be erected immediately to stabilise the structure and stop "demolition by neglect".
"It is ironic the buildings were under assessment for inclusion on the State register of heritage buildings, however, as that process is incomplete, the buildings have no legal protection under the State Heritage Act," he said.
In response to a request from _The West Australian _, the department released a copy of a structural assessment of the damage, which said scaffolding should be installed to stabilise areas prone to collapse.
A follow-up email from principal engineer Max Naismith said areas of brickwork were unstable and in danger of collapse.