Students at the school run by secretive Christian community Gloriavale sit qualifications up to three years early so they can focus on a more "practical" education - including laundry-folding for girls.
Students do not progress past Year 11, and are not offered external exams. No students in recent years had progressed to university.
Instead, in their senior years, girls and boys are taught separate vocational subjects - females learn sewing, cooking, laundry and childcare while males learn carpentry, engineering and farming.
Among the standards offered are how to "sort laundry items", "prepare and cook hot cocktail food", and "handle and treat sheep".
One education researcher has called for the 164-strong Gloriavale Christian Community School to be closed on the basis that it deprives students of human rights, but principal Faithful Pilgrim says that is "sheer nonsense".
"Our aim is prepare our own students from our community for a life of practical service, a life of faith within the community," he told the Herald.
"We're not preparing our students for a life in your society, we are preparing them for a life in our society. Otherwise it wouldn't be sensible, would it?"
Mr Pilgrim said the New Testament was very clear about women and men having different roles to play, which was reflected in the school curriculum.
He denied the practice of segregated subjects and early leaving ages was removing opportunities.
"Our girls get opportunities that girls in your society wouldn't come close to," he said.
"If they want to go to university and become a teacher they can do that, but we are not going to force them down an academic pathway."
NZQA statistics show only 55 per cent of Gloriavale Year 11 students achieved NCEA Level 1 or 2 last year, but Mr Pilgrim said that was because many of his students did NCEA - including English, science, maths, art and music - at Year 10.
He said of the school's 14 Year 10 students from last year, seven passed Level 3, six got Level 2 and one got their literacy and numeracy credits.
"We don't like to boast of our successes because as soon as you do someone is going to try and pull you down, but the NZQA statistics are ignoring the fact that most of our students achieve early."
Quality Public Education Coalition co-convener Liz Gordon said there was "oppression" at the school and it should be closed.
Ms Gordon said the school, which was government-funded to the tune of $199,316 in 2014, was limiting student opportunity, self-esteem and autonomy.
"It meets the needs of the community in that they're only interested in what kids can do to further the goals of the community. Which is to work in farms, in kitchens, and have a lot of babies."
She said if the children instead went to the local school, the state could be assured they were getting the same type and quality of education as other children.
The Ministry of Education said that while schooling was compulsory only until age 16, it encouraged students to stay at school longer because it increased the likelihood of success in later life.
"A longer education is linked to higher levels of skill and knowledge, which are required for taking part in our increasingly knowledge-based society."
Ultimately, however, it was the student and their family who made decisions about how long a student stayed at school, the ministry said.
The school's latest ERO report found that the curriculum "suitably meets" the Gloriavale philosophy.
"Students are well prepared to learn the necessary literacy and mathematical skills and appropriate relationships for a life of faith and practical service within the community," the report said.
Gloriavale has come under scrutiny after allegations of inappropriate relationships between children and adults and harsh punishments for children. The church's leader, Neville Cooper, was convicted in 1994 for indecent assault on young women, serving 11 months in prison.