It was extraordinary but I was shocked. When I was told I was on the longlist I thought it was lovely but I thought I’ll never be on the shortlist, so winning was just amazing. It’s extraordinary to suddenly find yourself at the centre of something so unexpected. The awards were a beautiful evening.

I usually start by saying it’s about a man who lives in a house in which an ocean is imprisoned. His house is immense. It is possibly infinite, although the narrator has no way of really judging whether or not it actually is. He spends his life wandering this house, which is an arrangement of large holes, vestibules and staircases. The walls are all lined with statues, none of which are the same. He leads quite a hard life because he has to source his own food but he still finds it full of beauty and meaning. He doesn’t know of any other world.

He’s happy. He’s curious and he is madly enthusiastic about finding out about his world. He does so in a scholarly way and constantly wants to know more, finding it all wonderful.

He’s happy. He’s curious and he is madly enthusiastic about finding out about his world. He does so in a scholarly way and constantly wants to know more, finding it all wonderful.

It’s interesting because when I started to write it seriously, my first idea was to present a person who was angry at the situation that he found himself in – but it just didn’t work. It just didn’t come together. It’s only when I realised no, he actually loved being there and he’s happy, only then did it all start to come together. This surprised me as much as anyone else.

I think the idea of The House and the two main characters all came together at once. It was a setting that needed someone to explore it and the people needed a reason to explore it, or you’re not going to get very far or learn much from the narrative.

In both of the books I have written, there’s been a contrast between magic and knowledge. Knowledge or magic can give you power over other people or help you acquire something for yourself – and that’s the sort of magic that ‘the Other’ is interested in. Then there’s the magic or knowledge which is really about making a connection with the world and experiencing life in a richer, fuller way. That’s the way Piranesi sees it. He’s just trying to understand the world and appreciate it, so they’re on opposite ends of the spectrum.

I only found out quite late on when I was writing how important they were. I suddenly realised, of course, these statues mattered and they were all going to be different. I wanted The House to have this dreamlike feel, like a place that you’ve never thought of before but at the same time, like a dream that is quite familiar.

I think a lot of people have dreams of wandering through an endless house, through corridors and rooms and so on. I didn’t want these statues to have a fixed meaning because I wanted them to be like images within a dream, where the reader can decide for themselves what they mean.

Yes, although I found out quite late on what the narrator’s name was going to be. It was a later acquisition but I’ve loved the work of the Italian artists for years. Lots of the artwork has this atmosphere of beauty but it’s sort of a melancholy beauty, which fascinates me. Giovanni Piranesi’s imaginary prisons (which are probably his most famous work) cause mixed reactions but some people find them grand and beautiful. Once I plugged into that, it seemed obvious what to name the narrator.

Thank you. Yes, I think combining a melancholy mood with beauty can make something linger for longer in the mind. It’s an atmosphere people can really latch on to.

As a child, I loved the Sherlock Holmes stories by Arthur Conan Doyle. I think in a way the books that stay with you for the longest are the books you read as a child. I tend to go back to those. I also love Edith Nesbit who wrote The Railway Children but she also wrote some magical books like The Five Children and It, as well as The Phoenix and the Carpet. Also books by GK Chesterton, who had a very distinct way of writing descriptively and making ordinary things seem fantastic. He would make London in the early 20th Century sound like a fairyland.

Yes, I think you enter those books in a much more complete way. When you’re a child you’re not thinking, “is this a good book or not?” You let it take you over and that’s why I think it can be a deeper reading experience.

I’m reading Patricia Lockwood’s book No One Is Talking About This, which I’m finding extraordinary. Reading her writing is like when you visit an art gallery and then when you come out, you see the whole world in the style of that artist for a while. It’s amazing. I’m also reading an old detective novel by Margery Allingham called Police At The Funeral. I love detective stories.

My advice is always just to concentrate on what’s best for you – don’t worry about what other people are doing. Write about the things you are drawn to; whether it’s something you know well or don’t know well, it doesn’t matter. If you feel a strong pull towards it, write about it.

Great question, I almost don’t want to give an answer. The pleasure of reading is that we always take away something different, depending on who we are. I wanted to create a unique character in Piranesi to teach us that what is valuable about his life in the house is his connection to the world around him. I think that’s something we’ve lost a little bit in this day and age and a loving relationship with the world around us is something we would benefit from regaining. Yet I want people to find different things in him, the story and the setting.

My pleasure, that’s really wonderful to hear. I have to admit when I finished the book and it went to the publishers – when Piranesi went off into the world – I really missed him. He was an amazing character to be with and a great companion for me. So that means a lot.