Now he is going to be racing the big boys of the senior school ranks. He's already been doing that in triathlon, his favoured sport, and recently finished second in the ITU Oceania U23 sprint triathlon champs in Kinloch. Running, naturally, is his forte in this exacting sport. But though he trains with real discipline, he is careful not to overdo the mileage, and though he works out twice a day, he jumps on the bike or in the pool to complement his daily run.
There will be time later for the Arthur Lydiard-type volume of training. For now, he comes under the watchful eye of former Olympic triathlete and 1996 ASB Young Sportsperson of the Year Nathan Richmond. The late Jack Ralston was also an inspiration.
He is also mentored by the head of Westlake's athletics programme, Theuns Strydom.
"Dan is an exceptionally talented athlete, but that is only half of it. You will have to go a long way to find a more determined, disciplined and hard-working athlete," says Strydom. "I am not sure how many athletes, let alone a 15-year-old, commit to what he does. I believe we are seeing the talent and the hard work coming together. When you get this the potential is unlimited."
Strydom has no doubt Hoy could make it as a middle-distance runner, but knows his true love is triathlon. Hoy is heading to August's Youth Olympics in China and he's got his eye on the 2020 Olympics in Japan, by which time he will be 21.
The school athletics programme comes to life closer to the end of the year, so for now Hoy's focus is triathlon, but he finds the crossover to other disciplines such as duathlon, cross-country and road running all easy enough to deal with, not to mention fitting in schoolwork.
Lean, fit as a buck rabbit and focused, there seems little reason why Hoy cannot achieve most, if not all, his goals in the coming years. He holds four Westlake school running records and there may just be a few more to come.