Principal Kim Blackwood said the rebuild was nearly finished and was expected to be completed in late March.
The school was founded in 1848, making it the oldest in Otago.
The $10.9 million project was eight years in the making and began with demolitions early last year.
The school adapted to losing half its classrooms by holding classes for older pupils at nearby Otago Boys’ High School.
The new building will house all 190 pupils as final demolition and landscaping work continues late next year.
The infant primary building, constructed in 1877, will be retained as the last memory of the school’s settler history.