Dr Irvine spent 10 years at the medical centre before he and Dr Leonie Sinclair decided to set up a practice together, buying an old house which they flattened to build the Eruera Medical Centre. For the past four years Janette has also worked at the practice, which means she too will be retiring.
Dr Irvine said it had been wonderful to have had such long associations with his patients.
He said one of the saddest changes in the GP role over his career had been the fact they no longer delivered babies. Other changes had been the increased role of practice nurses - "when I was first in practice we did everything, we didn't have nurses" and computerisation - "I don't know how my pharmacist used to read my prescriptions".
Then there's the growth of multi-doctor medical centres and the demise of solo GPs, which he believed was a shame for patients.
At just 62, Dr Irvine admits stepping away from his practice wasn't an easy decision, especially as he and his wife hadn't planned to retire just yet.
However, his replacements - husband and wife Dr Roz Wilson and Dr Grant Phibbs, formerly of Owhata Medical Centre, made him an offer he couldn't refuse.
"I thought about it and, well, in two years' time there may not be someone who is keen to buy me out of the practice ... so it was opportunistic, really." He is confident he has left his 1500 patients in good hands and pleased Dr Phibbs will also take over his work at Cantabria Home & Hospital - Dr Irvine has been seeing the elderly patients there for 28 years.
Dr Irvine and his wife will now set sail on their yacht for a month then spend a few weeks tramping in the South Island before they make a firm decision on their future. Aid work overseas is a possibility and locum work looks likely - it seems despite retirement this much-loved doctor is not quite ready to hang up his stethoscope for good.