Two of Christchurch's most prominent secondary schools could look to share teachers and classrooms under a new Memorandum of Understanding.

LISTEN ABOVE: Principal of Christchurch Girls' High School Pauline Duthie speaks to Chris Lynch

The relationship between Christchurch Boys' High and Christchurch Girls' High has grown since the earthquakes, when one built a hall, and the other a performing arts centre with the intention they be shared.

Boys' High headmaster Nic Hill said that worked so well they're looking to expand the collaboration into other areas.

"We're having a cyber safety evening later this term and it could well turn into sharing teachers, to sharing classes, just whatever opportunities we can find to our mutual advantage."

Both schools are now considering combining and sharing some classrooms and teachers for hard to staff subjects.

Mr Hall said sharing teachers for the hard to staff subjects like physics and maths would ensure both schools were getting access to the best educators.

"Students would get great teachers and they'd still belong to those schools with very strong, very positive identities."

But Girls' High also wants to stretch its smaller enrolment zone to match the size of Boys' High.

Board of Trustees Chair, Mike Lay, said it's been needed for some time.

"There is a lot of pressure on Girls' High. We have a very, very high number of students we have to turn away. We just want to make sure that we're giving the opportunities to those close to the school, and we just think it's a logical step.

"We've got some parents from Boys' High who cannot get their girls into Girls' High. We see this as being an issue, and with Christchurch realigning after the earthquake, we feel it an appropriate time to join those zones."

Mr Hall said the schools would welcome parent feedback on the arrangement, but the details are still being finalised.