When he was invited to architect Ernest Ford's home, he was captivated and found his path. Herbst now calls that house: "a rigorous experiment in concentric circles", but in his youth, he probably called it "cool".
He decided to study architecture and his parents breathed a sigh of relief.
On completion of his degree, he was offered a partnership at Ernest Ford and thrown full tilt into the deep end of his profession. "I was not well enough equipped for it. I had yet to find my own strength."
The first house he designed was on a steep hillside and echoed the idea of those circles within circles he'd been so taken with. It was a complicated project complete with attendant complications. "I think it's still standing," Herbst jokes. "Looking back, I can see my intention with that house but the way it was resolved was, well ..."
These days, with the constant sounding board of his architect wife, Nicky, he's more centred and assured. "It has taken me 20 years to learn how to make a building properly. I liken it to playing an instrument; it's only when you are a very fluent musician that you can start to think more emotionally about the process."
It's this layer of emotion that elevates the designer's art and the Piha holiday home that is the Home of the Year is a sublime example. The site, blanketed in mature pohutukawa, was certainly special but lesser architects would have run a mile from the red tape and vocal community.
"The pohutukawa is not only protected but much-loved. The section also occupied a space on the beach where there was a continuous swathe of these trees," Herbst explains.
Disturbing the environment as little as possible became the number one criterion. The result is a house that gets in among it so stealthily that it becomes almost imperceptible. Built under the tall canopy, on light legs that will not damage the tree roots, it emerges at night as a subtle glow from the forest.
The basic layout is of two bedroom towers joined by a central living zone.
Here, geometric tree-like supports hold up the roof which is partially glazed to let in the view from above. "It's an ambiguous space," says Herbst. "You feel you are neither inside nor out."
Metaphorical references don't end there. Irregular black-stained battens form the "skin" of the towers and allude to the rough bark of a tree. Inside these structures, the walls and ceiling are clad in light ply to emulate the pale innards of a stump.
Herbst is a master of the detail in design, somehow combining mathematical precision with an over-arching organic influence.
"We constantly refer to the genesis of modernist thinking - to people like Le Corbusier and Alvar Aalto who had a very sensual way of working with form and materials," he says.
Away from the drawing board, he likes spend time at the couple's bach on Great Barrier Island, to surf as much as possible and play guitar "extremely badly". He seems less comfortable talking about these subjects and inevitably, the conversation swings back to design.
After reeling off a list of his favourite indie bands - Destroyer, Villagers and the Pains of Being Pure at Heart - he recounts a lovely story fellow architect Ken Crosson told him that involved architecture and music.
"It was about a house Ken designed for a classical musician that was clad in 'irregular' battens that actually represented notes. The owner could read the facade of her house and play a concerto from it," he says gleefully.
When he finds time, movies are a happy distraction. "I'm a big Coen Brothers' fan and must have watched the Big Lebowski 10 times. Lars von Trier's The 5 Obstructions is a brilliant piece that keeps my friend, Kevin, and me in conversation, and I thought Baz Luhrmann's Romeo and Juliet very strong."
Until recently, as seems to be de rigueur in the architectural fraternity, he owned a classic European car. The Peugeot 504 convertible he brought with him from South Africa has since been sold. "It was a beautiful design, a cross between European and American styling, like a small flat slab," he says. But his workload became such that the car needed more TLC than he could offer. He surrendered it to a more attentive owner. He drives a silver Audi now, but when asked which vehicle he'd never own, this ecologically sensitive architect's answer is obvious. "I wouldn't be seen dead in a Hummer."
Keen to evolve his art and his business sense, Herbst reads widely. He's just finished Steve Jobs' biography and is now immersed in a book by Japanese architect Kengo Kumo. Tokyo-based Kumo advocates architecture that "disappears" rather than that which is self aggrandising. Kumo calls this approach "anti-object".
Herbst needs little prompting to explore this philosophy but he is able to contextualise the argument. "In some instances, architecture has to be about 'object'. If a building is going to displace space, which it will, you may as well make it a noble quest."
He singles out Frank Gehry's work as a soaring example of this. "And we wouldn't have the Sydney Opera House without this approach. It's a confident piece of sculpture."
Herbst knows he's come some distance from those naive concentric circles of his early designs. He does not veer wildly away from the self-taught lessons he's absorbed along the way. "Part of me says you should be taking quantum leaps into new things all the time but, as one gets older, you realise the value of moving forward in small steps."
