The school is set to merge with South Fremantle Senior High School, which will re-open in 2018 under a new name, tentatively called Fremantle College.
The existing Lefroy Road site will undergo $30 million worth of upgrades, with costs to be offset by the sale of land tenanted by HSHS.
The HSHS site is 15.3 hectares in size.
Education Department executive director of infrastructure John Fischer said land value will depend on the re-zoning and redevelopment proposed for the released land.
That process will begin when the school closes at the end of next year.
“Funds from the sale of the land will be returned to the State Government,” Mr Fischer said.
Mr Fischer said Fremantle College was progressing well.
“The department is currently going through the tender process, with construction due to be completed late next year ready for the college to open for the start of the 2018 school year,” he said.
HSHS principal Donna McDonald said the school had developed a framework to ease the burden on students and staff when the move takes place.
“Last year the Hamilton school community had significant input into the building design and plans for the new Fremantle College,” she said.
“We are working closely with regional office and looking forward to being a part of the College’s development over the next two years.”
A host of Cockburn and Fremantle schools will receive extra maintenance work under a multimillion-dollar top-up program announced by the State Government last week.
The work involves repairs to classroom ceilings, plus the removal of tripping hazards and millboard containing asbestos.