The cost of repairing Avonside Girls' High School looks set to blow out to more than $20 million.
The Ministry of Education is expecting to foot a bill of $100 to $150 million to repair the school network in Canterbury.
This includes state schools in the Christchurch, Selwyn and Waimakariri areas.
A Ministry spokesman Jerome Sheppard said the final cost of repairs to Avonside will be dependent on the long term solution but estimated it would exceed $20 million.
Avonside was the most severely damaged state school in the February 22 earthquake with two large blocks having to be demolished. It has been site sharing with Burnside High School but returns to the school site at the beginning of the 2012 school year.
Principal Sue Hume was aware that there would be significant costs to repair the school buildings. She said great progress was being made with the relocation moving from a demolition phase to construction. Many relocatables have been placed in position and the new buildings, technology rooms, science laboratories, general classrooms and library, are progressing well.
The tight timeline for work completion allows staff on site to unpack and set up classrooms from January 31. School will begin for students on February 7.
"It has been a year of significant disruption and we are all, staff, students and parents, looking forward to a return to some normality."
Ellesmere College sustained the most damage in the Selwyn district costing about $700,000 while in Waimakariri, Kaiapoi Borough School was the most damaged state school with repairs expected to cost $1m.
Mr Sheppard said the ministry has brought in 72 relocatable classrooms to provide necessary space at schools where classrooms cannot currently be used.