The Glenavy School roll grew from 100 to 155 by the end of last year due to an increase in dairy-farming families moving into the area.
The state co-educational primary school has a high percentage of dairy farmers in the area, mostly men, predominantly from the Philippines and Sri Lanka.
Due to the new immigration policies the farmers were able to bring their wives and families out to New Zealand to join them.
Glenavy School principal Kate Mansfield said the increase in the school roll was "massive" for a rural school.
"It’s a great thing for our wee school, but it’s just tight at the moment", she said.
The increase of pupils had required an expansion process at the school.
Three pre-fabricated buildings were expected to be delivered to the school, with the help of the Ministry of Education, before the end of the year.
"One is going to be split in half to have break-out rooms, so basically two new classrooms", Mrs Mansfield said.
Due to some pupils leaving this year the current roll was 136.
Over half of the school were English as a second language (ESOL) learners and the school had set programmes to provide for and support those pupils, she said.
The school held multicultural days to "celebrate our Filipinos, Samoans, Tongans, Chinese, Jamaicans, lots of different cultures".
"We are lucky we have a Filipino teacher aide and she is amazing at ‘defuzzing’ all of our New Zealand language.
"Like when you say ‘bring a plate’, you know, just that Kiwi slang."
Mrs Mansfield said they were the loveliest of children to teach and the multicultural school was a lovely place to work.
Throughout her eight years of leading the school the usual school roll increase each year was about 10 pupils, and with dairying being the main industry, the school used to be "very transient".
"We would have 100 students, every June ... and a quarter of our school would leave and go to other farms and areas, but now we’re seeing farmers and people staying at the school and not moving from it."
