They say everyone’s first novel is a veiled autobiography, so how did I come to write a novel about a window cleaner who finds himself hanging off Europe’s tallest skyscraper, the Shard?

Well, this isn’t technically my first time. In 2010, I read back through my recently completed first novel about a (handsome) young man called Alex who moves to London and gets depressed because it’s the recession. In a sort of weird homage to Greek tragedy, he also inadvertently has sex with his estranged twin sister. It was a masterclass in fiction, you see, because I don’t have a sister.

Imagine how disappointed I was when I read it back. It was not only tooth-achingly pretentious (each chapter was based on one of Kafka’s Zurau Aphorisms), but the plot ended about two fifths of the way through the book. Characters would sit on benches for whole scenes, thinking about how nothing was happening. The Irish critic Vivien Mercier once said that Samuel Beckett’s Waiting for Godot was a play ‘in which nothing happens, twice,’ and I guess I was trying to beat old Sam’s record.

After a month’s slump, I realised that I had learned two very important things. First, my book was so unremittingly bad that I didn’t have many mistakes left to make. Second, I now knew I was capable of completing a novel in the gaps around a full time job. I realised, to my horror, that what I had really done was pave the way to write a first novel.

I tried to stop myself. I met up with friends. I took up jogging. I even bought a bonsai tree. It was tiny and almost impossible to cultivate without killing – it didn’t cry when I did something wrong, it just quietly shed leaves. But as I stood there, pruning cautiously with kitchen scissors, I could feel my mind, plotting something new.

So I set myself some ground rules. If I was going to write a novel, it had to work first and foremost as a good yarn, a fireside story. It was only allowed to be as sad as it was funny. It should give a voice to some characters that felt genuinely unique. It also had to deal with proper problems like grief and morality, not fake problems like being a graduate with ennui.

A character began to take shape. I knew he wasn’t a detective, a lawyer, a doctor or a writer. His outline was… Portly. He had glasses. He was holding a squeegee. I’d never read a novel about a window cleaner before. It felt novel. I named him Günter Glass.

I realised I knew what Günter’s family was like. His brother was deaf, although that made people assume that he was nice, which he wasn’t. His father drank too much because Günter’s mother wasn’t around anymore. His girlfriend claimed to be clairvoyant, but could only see five seconds into the future; his landlord was an hermitic philosopher who ate only fish; his boss was proud to call himself a fascist.

By giving my characters their own lives and concerns, I forced myself to open up about issues that we can all relate to. Through Günter, I started to ask what it means to be human beyond the everyday: to grow up, to love, to die. Günter doesn’t get everything right, of course, but I’m proud of him. He has a good heart, he knows how to laugh – and if there’s one thing window cleaners have in spades, it’s perspective.

First posted on the Waterstones blog.