Ministry of Education figures show the school's roll dropped from more than 100 pupils a decade ago to just 73 in 2009.
But board chairman Gabe McGregor said the roll had grown consistently since 2011 - from 80 pupils in four classes to 140 pupils in six classes.
He said the school was nearing its 150-pupil capacity, and any future growth would increase class sizes, which might affect the quality of education at the school.
The school has been consulting the ministry to see if more classrooms could be added.
However, the ministry advised that ``property solutions'' would not be considered until an enrolment zone was implemented to manage further roll growth, he said.
``It is currently unclear what the enrolment zone will look like because the school is still in consultation with the neighbouring schools.
``And following that, final approval will need to be granted by the Ministry of Education before any enrolment zone can be implemented.''
Mr McGregor said all present enrolments would be accepted, and any enrolment zone would be managed as laid out in the Education Act 1989 and associated Ministry of Education guidelines.
It was hoped consultation would be completed in time for the enrolment zone to be in place for the start of the 2017 school year, he said.
``Parents are spoilt for choice of high quality schools in Dunedin, and Bradford has a reputation as a welcoming school that meets each child's needs, promotes a proactive culture of values, has a green environment and real sense of community.
``We also involve children and whanau in decision-making, which appeals to many families.''
