He said it was an exciting time for the staff as it wasn't just the school buildings that were new, the "intermediate" concept itself was relatively modern.
"Everyone was quite keen as it was brand-new ... they had 'decapitated' the schools to take the Form Ones and Twos out of the primaries and put them into intermediates.
"We didn't have a lot of staff so class numbers were relatively large - mostly over 42, no one had under 35 in their class. We peaked at about 640 kids - we had prefabs, two new blocks - there was an awful lot of kids jammed in."
Mr Rountree was occasionally called on to do science and art as the school couldn't find a dedicated teacher, but for the most part he ran his own general class.
The biggest changes he saw in his career were the introduction of information technology and the removal of corporal punishment, which he thinks is part of why males have largely disappeared from the classroom.
"We were 50/50 at the start - five men and five women - but now it's more like 80 per cent women. "
He said the increasing number of digital devices was having a detrimental effect on Kiwi schoolkids' reading and writing skills, as well as the obvious problems caused by powercuts at school.
"In the old chalk-and-talk days you didn't have to worry about that, you could keep going," he points out.
Events commemorating Rutherford Intermediate School's 50th Jubilee begin on Friday and include a black-tie dinner on Saturday and culminate in the unveiling of the Jubilee Plaque on Sunday.