A fierce fire that ripped through an unoccupied Sydney public school is likely to delay the 2019 completion date for the state's first high-rise high school and multi-storey primary school on the site.
The blaze broke out in a heritage building at the old Parramatta Public School on Macquarie Street in the early hours of Saturday morning, with fire investigators now looking at whether the blaze was deliberately lit.
The heritage building was part of the new $220 million Arthur Phillip High School and Parramatta Public School project, which was due to be completed by next year.
"With a heritage building being damaged, the project could be delayed," a spokesman for the Minister Education Rob Stokes told AAP on Sunday.
The new high school is set to cater for up to 2000 students, while the primary school is being built for up to 1000 students.
Parramatta Public School students had been moved from the Macquarie Street site into a temporary school on O'Connell Street at the start of the 2018 school year.
The Arthur Phillip High School students are currently in a nearby pop-up school.
The redevelopment project has already suffered delays due to prolonged wet weather, along with the discovery of two separate major archaeological finds in 2017.
No one was inside the heritage building when the fire took hold on Saturday morning but about 300 residents from a nearby apartment block were evacuated.
© AAP 2018