When I read that Alexander McCall Smith had bought a small chain of islands off Coll, I looked them up online.

The estate agent's pictures showed a couple of shots of a small modern house, but the seller was more keen to stress the beauty of these tiny Hebridean islands than the home their lucky owner would inhabit. The bobbing heads of seals dominated the gallery. They, and a colony of seabirds, will be McCall Smith's nearest neighbours when he takes ownership of this exquisitely lovely and lonely place.

Known as the Chains of Coll, this is almost as reclusive a retreat as a bestselling author could wish for. As the images scrolled past, if you listened closely to the wash of waves on private white beaches, you could almost hear the grinding of teeth in the JK Rowling and Dan Brown households.

For writers handcuffed to the publicity circuit or hounded by the press, this outpost of solitude, reachable only by boat and then only in good weather, is as much heaven as haven. There's no chance of unwanted visitors dropping by unless they've got flippers, beaks or gills. If McCall Smith needs only a pint of milk while slaving over the keyboard, it will involve taking his boat around the northern coast of Coll and down to its bijou harbour and high street where, the one time I visited many years ago, I recall there was a general store as well as a bistro and hotel restaurant and bar.

I was there to interview Rob Wainwright, former Scotland rugby captain and army doctor turned farmer. He's a handy person to have close, when winter storms close in and Oban suddenly seems further off than a mere 53 miles. Having said that, the author's wife is a doctor, so he's well set up for a long spell of seclusion. Yet much as McCall Smith would probably love to sequester himself on his island year-long, it seems reasonable to surmise he will restrict lengthy visits to less stormy seasons, otherwise his punishing schedule of worldwide talks and appearances might suffer. Then again, maybe that's the idea. What better excuse for missing a recording of Desert Island Discs than being stranded on your own Atlantic-battered rock?

Most writers – most anyone – will envy him his retreat. Personally I can think of few better ways to spend one's royalties, and I say that as one who gets seasick as soon as someone starts the diesel pump in a garage forecourt. But while those who work in the city occasionally long for tranquility, few need peace and space as much as authors. The surprise with a writer as prolific as McCall Smith is that up till now he has managed to write seamlessly without this luxury. I was struck, though, by his comments that in his Argyllshire retreat, his writing space wasn't quite right. Also, that he cannot write in an ugly hotel room.

It's astonishing how many writers need perfect conditions before they feel able to begin. Some have essential start-of-day rituals, such as drinking only from a particular mug, others have pens that must be the right heft, or notebooks of a specific brand. Height of table, depth of chair and silence of house are factors individual to each writer. Where the thump of a teenager's music would drive some to commit child murder on each page, for others too much solitude would be as off-putting as immersion in a bell jar.

I recently discovered the perfect place to write. Inspired by a traditional shepherd's hut described by Thomas Hardy in Far From The Madding Crowd, a Dorset company recently began making bespoke shepherd's huts, which can be parked in the garden at a companionable distance from fidgety loved ones. They come complete with stove, underfloor heating, bed or table, or bookshelves, according to taste. No doubt modelled on a gypsy caravan, these huts are a portable bolt hole. Nothing beats a private island, but at least these are easy to reach, whatever the weather. (For details go to www.plankbridge.com.)