Any book lover would find it hard to leave John Boyne’s home. One room is devoted to English literature, another to Irish and American books. On floor-to-ceiling shelves, fat trilogies, slender novellas and tall folios, ranked in alphabetical order, bring a benign presence to the Irish author’s house.

“I love being surrounded by books. That old quote, ‘Books do furnish a room’ holds true – even the colour of a spine adds character,” says Boyne, pausing to jam some more logs into the wood burner. “When you work from home like me, it’s important to feel safe and secure. Books are part of that.”

Boyne used to share this four-bedroom house, in Dublin, with his partner; but when they broke up 18 months ago, he decided it was time to re-invent it. “We’d been together for 11 years so, to be honest, a great deal of it was clearing out memories and starting from scratch. I didn’t want to leave this house, as my parents and sisters live nearby, but I wanted my home to be more than four walls that hold me. It had to be a place where I can always feel happy.”

Realising that he lacked “the good visual eye” needed to overhaul the interior, he enlisted the skills of interior designer Caroline Flannery. A few meetings later, Boyne cleared out his home. “I got rid of anything that didn’t make me happy. It was a cathartic process.” As the builders moved in, Boyne relocated to London to let them “go mad”. The result is a streamlined but colourful interior where many of the rooms have a new function: there is a reading room, a gym area and two work spaces.

“My brief was to transform my home. Apart from that my needs were minimal. I was keen from the start to have a log-burning stove. And more shelf space for my books was another pre-requisite,” says Boyne, the author of 15 novels including The Boy in the Striped Pyjamas and last year’s The Heart’s Invisible Furies, which charted Ireland’s gradual shift from repressive theocracy to liberal republic. “There’s something about the fact that we were late to decriminalise homosexuality, but also the first to legalise same-sex marriage by popular vote that I find rather wonderful,” he says.

We climb to the top floor, where the attic and landing were converted to create bookshelves that soar to the ceiling. A lavender reading room houses his collection of American literature. Elsewhere, clusters of books beckon from every room: a section of translated fiction here, another of non-fiction.

“I used to work at Waterstone’s in the late 1990s when my writing career was taking off,” he says, “so there’s an element of the bookseller in the way I arrange my collection. But I’m also an organised person and, as I have more than 7,000 books, I don’t want to feel they’re closing in on me.”

He describes the process of working with an interior designer as educational. “I’d always stuck to off white and more off white, but Caroline encouraged me to take risks.” Including the blush-pink desk? “Why not? After all it’s only paint, I can change it.” He’s also discovered more about bespoke craftsmanship. “I used to think that when you move to a place you rush out and buy everything in the shops – at once. But I’ve learned that it’s more rewarding to wait for the right thing.”

The wooden table in the living room, where logs are neatly stacked in a niche, was made locally. “I view interiors differently now. Even the simplest things, like a toaster or kettle, can make a home wonderful to live in. You can spend the same amount of money, but not go for the obvious choices.”

In the guest bathroom you find a sketch of Boyne by children’s author Oliver Jeffers, who has illustrated many of Boyne’s books, and framed pictures of a Lego version of the hero from The Boy in the Striped Pyjamas. (Boyne politely prefers not to discuss this title as, like many writers, he does not want to be “defined” by one book.)

Elsewhere, colourful Aboriginal artwork and a carved wooden shark were hauled back from Sydney where Boyne likes to spend every January. “I enjoy finding things that are beautiful, but also remind me of a place – as opposed to something that’s just an expensive piece of art,” he says.

Boyne delivered his latest manuscript to his publishers last week. He works seven days a week in a cabin at the end of the garden. “I call it my ego room,” he says of the peaceful space where pistachio green shelves are lined with editions of his own books, published in 50 languages, arranged with a stylist’s eye for colour and contrast.

“I’ve become more confident about the way things should look. Until now, interiors haven’t figured greatly in my novels. But perhaps now they will.”

A Ladder to the Sky by John Boyne will be published on 23 August