Hensman said he had given the Taradale High School Board of Trustees five-and-a-half months' notice to ensure there was time to run a rigorous recruitment process.
Board chair Liz Read said Hensman had been an outstanding and dynamic leader responsible for considerable change at Taradale High School during his tenure as principal.
"His compelling vision for Taradale High School, emotional intelligence and ability to influence others has resulted in the implementation of endless quality improvement initiatives during the last 12 years.," she said.
Hensman, currently the chair of the Hawke's Bay Secondary Schools' Principals Association and a part of the executive of the New Zealand Secondary Principals' Council, said the most satisfying part of his tenure at Taradale High School had been the gradual improvement in academic outcomes.
He may be leaving, but he is not retiring. After a short break, Hensman will begin working as an independent education consultant, and would remain in Hawke's Bay.