Tributes have flowed for highly respected teacher Barry John Allen who died this week after a medical event in his classroom while relieving at Greenpark School.

Greenpark Primary principal Gareth Scholes said Allen, aged 68, died on Tuesday after a sudden medical event at the school.

Scholes said emergency services were called about 10.20am on Tuesday, and police, who assisted ambulance staff, arrived at the school about 20 minutes later.

"Everyone at the school is saddened about Barry's death and a number of parents have commented that he was their favourite relief teacher," he said.

"Barry was a respected local educator who was committed to engaging adolescent boys in education and he also spent a number of years teaching at Tauranga Intermediate School.

"Recently Barry had relieved at Greenpark School and he was admired by students and staff, sharing his passion for learning and experiences in education.

"Our thoughts are with his wife Suzanne and her family at this time."

Allen also leaves behind his three sons and five grandchildren.

Scholes said Allen had been a relief teacher at Greenpark on and off for three years and he was highly experienced and a valued member of the school community.

"Barry recently told me he had been teaching for more than 50 years," he said.

"Relief teaching is a challenging role. But Barry was always excited about working in the classroom and his students really appreciated his teaching style, especially his storytelling.

"Barry was a really nice guy as well as a great teacher," Scholes said.

Board of trustees chairman Wayne Gribble agreed.

"Barry died while doing some wonderful things with the students at Greenpark Primary School," Gribble said.

"But Barry's legacy is far more than that. In particular, he also made a real difference to the lives of many young people during his time at Tauranga Intermediate," Gribble said.

"Barry was a very passionate educator, who had a real calling for his chosen profession."

Tauranga Intermediate principal Brian Diver said he and the other staff at his school were saddened to learn of Allen's death.

"Barry, who taught at Tauranga Intermediate over a long period of time, will be sadly missed by us all," Diver said.

"Barry made a significant contribution to adolescent boys' education at Tauranga Intermediate and the other schools he taught within the Tauranga area," he said.

"Our condolences and sympathies go out to Barry's family," he said.

During his time at Tauranga Intermediate, Allen also ran a breakfast club for students for several years.

In 2009 he also received Rotary International's highest honour - the Paul Harris Fellow award for "outstanding service to humanity".

The Rotary Club of Tauranga Te Papa nominated Allen for his direct involvement with running The Fitco Gym Boys' Club programme at Tauranga Intermediate School, a programme Allen began in 2004 which uses exercise and different learning styles for students who exhibited behavioral problems. The programme was adopted nationally.

Lyall Holmes from the Rotary Club of Tauranga Te Papa said at the time that Allen was nominated because of the incredible work he had done with the students.

"To experience the difference in these boys is nothing short of remarkable," he said.

Allen's more than 50 years in the teaching also included a stint as principal of Burnham Primary School in Christchurch and he also taught at a number of other schools.

They were Kaikohe Primary, Mangatuna School, Rangitukia School, Taita Central, Takaro School, Taupō Primary, Te Huruhi Primary, Te Rato School and Te Puia Springs School.

A service for Allen will be held at Waldorf School in Welcome Bay Rd today at 11am followed by a burial at Pyes Pa Cemetery.