WELLINGTON, Sept 13 - Around 100 firefighters from 13 brigades will attend the disused Taihape College for a series of exercises starting on Sunday, to give crews realistic practice in fighting fires.

Whanganui area manager Bernie Rush said the old school building will give the paid and volunteer firies an education in the stages of a fire's development and how to react.

"The scale of this exercise makes it unique for our crews and will present some challenging scenarios for them," he said.

He said the Fire Service regularly used building set for demolition for practice, but they are usually small rural houses or commercial buildings.

The course will run across three days in individual classrooms before the entire building is torched.

The 53-year-old school on the town's outskirts was replaced by Taihape Area School, which opened in 2009.