Inspectors believe the fire that destroyed an Auckland school's classroom block may have been deliberately lit.

Police are investigating.

Northcote College's technical block went up in flames on Friday night, destroying a year's work of some students who were finalising their portfolios for assessment.

Principal Vicki Barrie says the school has two weeks to get organised before students return from their term break.

She says they will be getting support from the Ministry of Education to help clear up the site and provide new facilities for students.