Classrooms at another school in Wellington are closed because of the risk of collapse in an earthquake.
Ngaio School on Friday announced the closure of three classrooms and its hall.
Board chairman Andrew Hudson, says the trustees weretold in January that a building had been judged to be earthquake-prone, but that there was no need to evacuate it.
Mr Hudson says that changed on Thursday night when engineers explained that the building's wall and floor were not well connected and could shear in a major quake.
Several other schools in Wellington have already closed classrooms or halls because of structural weaknesses.