For the past 18 months, much of the school has been a building site, operating with various buildings in a state of development.
However, principal Ben Sincock said by the time school starts this year, all but three of the 21 classrooms would be open for use.
''It looks fantastic.
''It's been a long road getting here, but now that it's all coming together, it's very exciting.''
He said the last three classrooms would be ready by February 22.
''It's mainly a clean-up job left to do.''
Mr Sincock said stage one began in mid-2012 with the construction of a six-classroom junior block, complete with a large learning space, and the refurbishment of a two-storeyed Nelson block.
Stage two began at the start of 2013, and involved the redevelopment of the school's two other two-storeyed Nelson blocks, the establishment of six new learning areas, a new technology centre and a performing arts area, he said.
College Street School, Caversham School and Calton Hill School were merged into Carisbrook School in 2012, on the Caversham School site.
However, after community consultation, it was decided to leave the Calton Hill site open as a second campus, with an option to review its viability in two years.
College Street School also remained open during 2012 and 2013 because there was no room for the pupils at the new Carisbrook School site until building developments were completed.
The project's completion means the school will have two campuses not three, and all 100 pupils from the former College Street School will be moved to Carisbrook School for the start of term 1 this year.
The third campus, the former Calton Hill School, remains open.
''Logistically, things will be a lot easier now that we only have two sites at the school,'' Mr Sincock said.
