A home near River Spey and Cairngorm mountain

The only trouble was, the more hats he sold the less chance he had to slalom down the runs. Next came a business based in Italy, teaching groups of British schoolchildren to ski. That, too, did well and it was how he met Tina, who shared his love of mountain sport and was to become his wife.

It was an enviable life, but eventually they decided it was time to settle down. The next stop was Bedfordshire, where Tina’s family were farmers. They married and started a family, built themselves a house and ran a business growing soft fruit.

The idea was simple — the strawberries would earn them a living in the summer and leave the winters free for skiing.

“The trouble was, the business just did too well,” says MacGeoch. It was his entrepreneurial instincts that interrupted play. He began to wonder why farms did not exploit the full potential of their land. So, years before most farmers learnt the meaning of “diversification”, his woodland playgrounds, cafe, pets’ enclosure and other such innovations pulled in 75,000 paying visitors a year.

There was an enormous drawback: success left no time to play. So, six years ago, they sold up and headed back to MacGeoch’s former stomping ground of Strathspey. He had yearned for the landscapes of his youth. “Bedfordshire is very flat,” he says at Drumuillie Lodge, sitting at a window with a spectacular view across the river valley to the top of Cairngorm.

“That’s the Lairig Ghru,” he adds, his finger tracing the profile of the well-used path that cuts through the mountains to Braemar, as though he is pointing out the detail of some fine painting that he owns.

The MacGeochs designed the house. They had caught the self-build bug in Bedfordshire, and MacGeoch says he enjoyed both the planning and the project management.

The earlier house had been a compromise, squeezed into a corner of the fruit farm. Strathspey is different: a long-abandoned croft sheltered by birch and pine woods yet also, thanks to some judicious felling, open to the sun and panoramic views. They used Scotframe, of Inverurie, to provide the components of the timber frame and employed an architect to hone their sketches and ideas into practical designs.

However great their practical abilities, self-builders seldom have the expertise to make the best use of space, walls and light; the very qualities that make Drumuillie such a special house. Clad in timber with a traditional slate roof, it could be described as Nordic with a Scottish twist, and the natural materials fit well with the rugged woodland setting.

Downstairs the living area is largely open-plan, yet alcoves and hidden corners balance modern style with a cosier tradition of comfort and seclusion. Upstairs, the bedrooms are all well-proportioned and MacGeoch’s daughters — Kirsty, 20, and Ailie, 17 — have what is virtually a private wing: a huge bedsit with the feel of a loft apartment.

“They could have had a room each,” says MacGeoch, “but this is how they wanted it, so this is how it was designed.”

Throughout the house there is a sense that nothing has been skimped on. A hawk-eyed manager who employed a local team, MacGeoch brought the project in on time and within his budget of £400,000; an outcome that very few self-builders achieve.

MacGeoch has since bought and renovated other properties in the area, putting to good use the experience he has gained.

“It’s a niche market that I’m into,” he says, “but it’s a market that I know and understand. If you’re offering the best, there’s always somebody who will want it, even if it costs a little more.”

His most recent project is The Grange, a former manse at Knockando. “It had seven bedrooms and just one small bathroom when I bought it,” he says. “Now they’re all en suite and there’s a huge modern kitchen with an Aga. That’s what people demand.”

Signs of the family’s enterprising spirit are also evident in Drumuillie’s gardens. For the most part, the five-acre grounds remain wild woodland, a peaceful, secretive retreat from the pressures of the world. Tucked away below the house, however, are three large polytunnels that house Tina’s productive market garden.

Her soft fruit, herbs and vegetables, including what have to be some of Britain’s most northerly grown asparagus, are sold in Strathspey’s village shops, proving a hit in a region not noted for its seasonal variety of vegetables.

Throughout the house there is evidence that the family’s ethos of work hard, play hard is shared by the younger MacGeochs, whose sporting trophies are on show in every room.

Kirsty is a noted swimmer, while Ailie has captained Scotland at rounders, but it is Calum who steals the show with an array of cups and medals he has won at tennis.

He is ranked No 3 in Scotland for his age and, given continuing commitment and good coaching, it is possible that he could go far in the sport.

His father says: “He knows what he wants and he’s utterly determined to succeed.”

It is young Calum’s will to win that has prompted the family to move home once again. For the next few years they will devote everything to nurturing his talent and, sadly, this means that they must leave the Highlands.

“This is a fabulous area,” says MacGeoch, “but for a tennis player, it’s the back of beyond. In the four years since Calum first picked up a racket, his mother has had to drive him 200,000 miles.”

So the next self-build project is likely to be somewhere less remote, perhaps with rooms that look out to a tennis court instead of the Cairngorms.

Drumuillie Lodge, Boat of Garten, is for sale for at offers over £700,000, The Grange, Knockando,at offers over £775,000, both with Knight Frank, 0131 222 9600, www.knightfrank.com