‘Lyra barged open the door, dragged her rickety chair to the window, flung wide the casement, and scrambled out. There was a lead-lined stone gutter a foot wide just below the window, and once she was standing in that, she turned and clambered up over the rough tiles until she stood on the topmost ridge of the roof. There she opened her mouth and screamed.’

Like Lyra in Philip Pullman’s Northern Lights and Sophie in Katherine Rundell’s Rooftoppers I also grew up on rooftops. My room was in the attic and felt like a cross between a Scandinavian log cabin and a tree house. Accessible only by a step ladder with a trap door to shut me in, it was my domain. The room also had two windows through which my kingdom opened onto the pitched roof and the rooftops of the adjoining two houses.

Up there I found uninterrupted views over the city, but also a sense of freedom, adventure and distance from the crowds. I’ve loved being on rooftops ever since, though am perhaps a little less reckless now. So it’s always a thrill to read a new story that takes place in this alternative rooftop world.

From the feather dressing Old Bailey in Neil Gaiman’s Neverwhere to the cat-suited Irma Vep in the 1914 French silent crime epic Les Vampires, all the coolest people are to be found on the roof.

Add to that number Sophie Maxim, and her creator Katherine Rundell both of whom have spent considerable time exploring the rooftops above Oxford, London and Paris.

‘I can’t stay off the roofs.’ said Sophie. ‘I need them.’ ‘Why?’ ‘I . . .’ said Sophie. ‘It’s hard to explain. They feel safe.’ Sophie blushed as she said it. The boy snorted. ‘I mean, they feel important.’

Rooftoppers is a piece of children’s writing in the classic mould. It’s like an antique adventure by Frances Hodgson Burnett with the same otherworldly sense of place and time as Joan Aiken’s Wolves series. This is a historical fantasy infused with a very modern sensibility – there are few places left for us to explore on earth, but the off limits world inhabited by real life rooftopping thrill seekers always inspires awe.

Sophie is orphaned after her parents are drowned in a ferry disaster and is sent to safety in a cello case. She’s discovered by another survivor of the disaster, becoming the ward of the kind, eccentric bachelor Charles Maxim. Sophie grows up in his house of books, learning the cello on the roof until the authorities decide her needs as a young woman would be better met in an orphanage. So they flee London for Paris, in search of Sophie’s mother, who she believes survived the sinking. Once there, they are thwarted again by the authorities. And as Charles attempts to navigate the bureaucratic pathways of the law, Sophie finds her way on to the rooftops of Paris where she meets lost boy Matteo.

‘She shouted, “I can see you! I’m not going to give in!” she turned a cartwheel. It was the most defiant cartwheel ever to have been turned on a Paris rooftop.’

Soon they are off on a breathless series of adventures across Paris, meeting a pair of equally indomitable girls who traverse the city’s treetops and avoiding the ‘garieres’, a feral gang who live in the station roofs and rule the territory around with cutthroat zeal. Unfortunately this is the very place Sophie believes she will find her mother.

Rooftoppers, like the other stories I’ve mentioned, is a book about outsiders. Matteo and his kind are living up high because of something terrible that has happened below. The spectre of growing up hangs over this story – as Matteo points out roofs are no place for adults to live. And while Sophie has the unwavering support of her guardian on the ground they have no reason to return to Paris below, and every reason to fear it.

I came down from my own rooftop for the last time today. The portal that has remained open until I was almost 40 has now closed but as my parents are about to leave the house. But I hope the rooftop adventure will be carried on by whoever moves into my attic. And if they need a nudge, maybe they’ll find the copy of Rooftoppers I’ve left hidden in the eaves.