The Ministry of Education has approved the demolition of the main classroom block at Newtown Primary School in Wellington.
The school closed the two storey block last month because it meets just 6% of the Building Code for earthquake resistance.
The school says demolition work will begin as soon as Wellington City Council issues the appropriate consents.
It says that is likely to be in February.
The site will be blocked off from the rest of the school so students have no access.
The school says junior students will remain in their current classrooms while the rest of the school will use prefabs in the school grounds while the block is rebuilt.