Last year Ōhaupō School was so crammed for space one of its classrooms was running from the library and the library was packed up.
The Ministry of Education has now recognised the Years 1 to 8 primary school needs to prepare for more growth.
It has a roll of 194 and by the end of the year principal Sue McLocklan expects it to be over 200.
The ministry has funded of a new two-classroom block that will also have a withdraw space, a learning support teacher space, a resource area and a kitchen.
It is being built by Construct Limited.