IF there was one Scottish novel in every bookshop window in 2016 it was His Bloody Project. Graeme Macrae Burnet’s examination of the mind of murderer Roderick Macrae was long-listed for the Man Booker Prize in June. Then it edged out the big guns of the literary world to make it on to the shortlist. Although it didn’t win, it outstripped sales of the other novels. In late November, Burnet was given his due when he won the Saltire Society Fiction Book of the Year Award. One week later, I met him – a tall, friendly, "ageing existentialist" – in a bijou coffee shop in Edinburgh’s New Town. It was a far cry from the brutal life of the Highland crofting community in Wester Ross where the drama of his novel plays out. The west end of Glasgow ("where," he tells me, "all the writers live") has been Burnet’s home for 15 years. But he grew up in McIlvanney country, Kilmarnock, where he was born in 1967. On his mother’s side he has family ties to the northwest Highlands.

"The main reason the book is set in that part of the country is because for my whole childhood we went up there three times a year to visit my gran, who lived 20 miles south of Applecross. I’m not a local but I know the landscape and it seemed very natural to set the book in a place I was quite familiar with. There are little things in the book taken from then. There is a character called The Onion, an old lady who wears multiple layers of clothes. She’s based on an old character in Lochcarron I knew about when I was growing up. I think those details are what bring a piece of writing to life."

His Bloody Project is presented as a collection of found manuscripts. Burnet poses as the editor, and even writes a "literary-journalistic" preface. On August 10, 1869, Roderick Macrae murdered three members of a family in the village of Culduie. He confesses to the crime but Andrew Sinclair, his advocate, hopes to argue that Roderick is not guilty in a "special defence of insanity". Sinclair asks Roderick to write a memoir to bolster the case. This provides the main bulk of the novel, but it sits alongside a report by criminal anthropologist James Bruce Thomson, testaments from the locals, and a write-up of the trial. I asked Burnet why he chose to fragment the story in this way. "What appeals to me about using this kind of structure is that because you have different voices there is no single one concerned with truth. The reader is placed in a very active position where he or she has to think through what Roddy’s motives are." The novel has been compared to James Hogg’s Confessions Of A Justified Sinner, but in its original conception it was closer to BS Johnson’s The Unfortunates, which is presented in a box with the chapters bound separately so they can be read in any order.

His Bloody Project has had a strange relationship with truth in the real world. Even some of our most esteemed literary pages have mistaken it for a true story, despite the word "novel" emblazoned across the title page. It has been called "true crime" and "historical fiction", both false appellations. Never underestimate the ignorance of critics or the gullibility of readers. "I’ve only got myself to blame," he says, with a small, knowing smile. It’s true, in a way. Burnet constructs are very believable conceits, and he’s a thorough researcher. "One of the inspirations was a French case from the 19th century where a peasant called Pierre Riviere killed three members of his family then wrote an eloquent memoir about it … there is something fascinating about the apparent contradiction between these acts of violence and this articulate writing." It brings to mind Humbert Humbert’s infamous utterance in Lolita: "You can always count on a murderer for a fancy prose style."

Burnet’s sentence craft has been influenced above all by the two Georges: Orwell and Simenon. Indeed, "the psychology of character", which Simenon mastered, is partly what makes His Bloody Project so compelling. "Simenon writes with a brilliant economy. He evokes place in the simplest of language." Burnet talks about his love for Orwell’s Down And Out In Paris And London. "The opening, when Orwell is looking out his hotel window and describing the street below, is a model for my writing. To make it seem so simple is a real art." Burnet’s attention to the eloquent simplicities of language doesn’t come from growing up in a house full of books. His was "a fairly middle-class family. They read a book in bed but they’re not literary types at all. So when I discovered books I discovered them for myself".

He was at Glasgow University studying literature when he realised he could make money from writing. "There was a writer in residence then called Hunter Steele. I was writing these pseudo-Samuel Beckett stories and I put a couple in his dookit and – terrified – went to hear what he had to say. He said: “Have you ever thought about getting any of these published?” The thought had never crossed my mind. I hadn’t been brought up in a world where that happened. I don’t come from an under-privileged background in any way, but you need to know it’s possible to do something like this."

Burnet's breakthrough didn’t come for a while. After university he taught English as a Foreign Language in Prague and Bordeaux during the early 1990s. He has also worked for a television company, an experience which has helped him this year, on the other side of the camera. His writing career took a turn for the better when he won a Scottish Book Trust New Writers award in 2013.

How does his life now compare with how it was before the Booker? "I was quite happy with where I was. I had published two books. But was I making anything approaching minimum wage? Absolutely not. I did other jobs to fund my writing. Has my writing life changed? It’s completely transformed. I can be a full-time writer. The book is selling in reasonably large quantities. It’s a big change." It is the irony of life as a 21st-century author that although Burnet now works five days – if not more – a week there isn’t necessarily more time for his art. "I had three or four months when I didn’t write a thing because I was too busy doing public appearances." But this unexpected break from his normal routine gave him space for reflection. "It gave me time to think about how I got into this position. First, I wrote a book about a very obscure town in France and pretended I translated it [The Disappearance Of Adèle Bedeau]. Then, instead of writing the next in a series of detective novels, I wrote a book in found-document form set in a 19th-century crofting town in Scotland. If I'd had my eye on a commercial career path I wouldn’t have made those decisions. I’ve been lucky to have had a publisher who supports me, and doesn’t say, 'Don’t write that, write another detective novel.' You feel the pressure, but you just have to put it to the back of your mind. I’m just trying to get back to writing now."

He knows any new work will be seen in the light of His Bloody Project. A week after the Booker Prize announcement Burnet aired his nerves to his publisher, Sara Hunt of Contraband, an imprint of Glasgow-based Saraband. "Sara said, 'Chill out, you don’t even have to write anything.' If I told her I wasn’t, she might be a bit disappointed. But it took the pressure off." Since then, he has found a way to concentrate on writing. He doesn’t believe in being falsely modest about what he’s achieved yet clearly understands the dangers of over-confidence. As you read this, he will be back at the coalface – The Mitchell Library in Glasgow, his informal office. He’s using the slow winter months to work on a sequel to The Disappearance Of Adèle Bedeau. As proof, he pulls out a well-thumbed copy of John Paul Satre’s The Age Of Reason. He always reads what’s relevant to his writing "so I am mentally in the space of the novel". But he can’t spend too much time in preparation. "The longer the wait for another book, the more expectation there will be. The first book was very small-scale. It’s a character study and a quiet little book, and the next one is a quiet book, so I don’t want this huge expectation on its shoulders."

He knows now the media spotlight has dimmed, he has to knuckle down. After all, there’s not long until he’s on the road again. In March he’ll be touring New Zealand, Australia and Estonia with His Bloody Project. He’s looking forward to the trip, and as we head out into the cold night, the air ringing with carols, he doesn’t look concerned in the least about the task ahead. Full-time writers don’t have enough hours in the day for worry. Nevertheless, should the doubts creep in, Burnet can always turn to one of his favourite authors. Simenon, he tells me, bashed out some of his roman durs, or "hard" novels, in 11 days. Now, that’s time well spent.

His Bloody Project is published by Contraband