Education Minister Hekia Parata says Christchurch high schools will be ready to take younger students from intermediate schools that are closing at the end of the year.
Seven Christchurch primary and intermediate schools will close, three primary schools will merge and three secondary schools will expand to accommodate displaced students.
Of the closures confirmed on Wednesday afternoon, most will take effect from January 2014.
Branston, Linwood and Manning intermediates are three of the schools to close. Hornby High, Hillmorton High and Linwood College will from next year expand to provide for Year 7 and Year 8 students.
Some of the intermediate schools are worried the high schools won't be ready to take the younger pupils.
Manning Intermediate principal Richard Chambers says the short timeframe places pressure not only on the three high schools, but on his soon-to-be jobless teachers who will be expected to help with the changeover.
Mr Chambers says such significant decisions for Christchurch should have waited at least until the results of the census are released later this year. He says families aren't yet settled and there are strong indications that the city's population is rising due to the rebuild.
Branston Intermediate principal Jennifer O'Leary says it's a social experiment and there isn't enough time for the secondary schools to have the resources in place for the influx. She says many of her students will be taken on by Hornby High, which needs longer than eight months to prepare.
Ms O'Leary told Radio New Zealand's Morning Report programme the intermediate age group of mainly 11- and 12-year-olds have very different needs, both socially and academically, to older students and secondary school teachers are not trained to deal with them.
However, Ms Parata told the programme that she and ministry representatives have met with the principals of the receiving secondary schools, who feel that with appropriate resourcing they will be ready to accept the younger students.
"We are talking about a profession who are familiar with the curriculum, who understand that at different age levels there are different needs and requirements, and I expect that these schools will be able to provide the necessary level," she said.
"Change is hard but we can't ignore the reality of the damage the earthquake has caused, of declining rolls, of population movement, of property integrity issues. We have to focus on how we build the best possible education system for the Christchurch communities."
Hornby High School principal Richard Edmundson says he's comfortable with the timeframe because the ministry has said it will help with new buildings, staff and teaching resources.
At least 100 intermediate pupils are expected to be taken at the school. Mr Edmundson says he has been thinking about the future since possible closures were announced last year and wants to build an adventure playground for the younger students.
Mr Edmundson says rather than moving to their different lessons, they will stay in one place and mostly be taught by the same teacher.