Another country: Artist Charles Avery discusses the Island

The 35-year-old artist has spent four years making work about the place he simply calls the Island. He has mapped its topography, drawn its inhabitants, created models of its creatures. It has become the focus of his practice, what he describes as "the defining project of my life".

Avery was one of the six artists chosen to represent Scotland at last year's Venice Biennale, the only one who did not go the Glasgow School of Art (he is largely self-taught), and the only one whose work is not predominantly conceptual. He is known particularly for his drawing, which one critic described his work as "probably the finest contemporary figurative drawings I've seen in the last 15 years".

His show at the SNGMA, created at the London gallery Parasol Unit, is five times bigger than any other solo show to date. It is an indication of how much work he has produced in the last four years. Last spring, when I visited his studio and saw him working on a large, detailed drawing, I assumed it was one of a handful on that scale. Now I realise it is one of many.

Avery draws fast and fluidly. He likes the medium because "it allows me to work at the speed I think". But he insists that he was not working at full capacity. "So much of the project up to this point has been about working out how to do a project like this – like a dog trying to get its teeth around a football. It hasn't been sheer production by any means.

"I'm surprised how well this show has come together. It was extremely well planned but I'm very pleased – it's not often that anything I plan comes together that well! This exhibition serves as a kind of beach-head, a position gained. It's time for an extended period of reflection."

The scale of the current show, taking up the space that housed the Tracey Emin retrospective during the summer, is an indication of the regard in which Avery is now held. Philip Long, senior curator at the SNGMA, first noticed his work at a show at doggerfisher in Edinburgh in 2002. "When we were selecting the artists for Scotland in Venice 2007, he was an artist we wanted to choose.

"I think he's an extraordinary talent. His ability as a draughtsman and his ability to produce images of the world which he has invented is quite extraordinary and really quite dramatic. Like a lot of great artists, his work makes an immediate impression, potentially to a wide audience, but it also offers the possibility of more and more intellectual stimulus, the more you go into it."

Avery describes being shown in Venice as "a great experience from start to finish". "Everybody in the art world was there. It was a great way of introducing part of the project to people. I hope the Scottish Arts Council sees the value of it and does it again, it's extremely good value for money in terms of what it does for the international profile of the artists who participate, and the knock-on effect in terms of how Scotland is perceived. It seems there is something eternally exciting about Scotland and Scottishness."

And the Island is definitely a Scottish island. Avery spent his formative years on Mull and once described it as "the total basis of my subconscious". "A lot of writers say: 'Write what you know', so I've based it (the Island) on my direct experience, which is growing up on the West Coast of Scotland, some time in Edinburgh, some time in Rome and a lot of time in Hackney. You'll find a distillation of these in the works."

While he freely acknowledges that the Island is "a fiction" and "an intellectual pursuit", a place for exploring philosophical ideas, he has a disconcerting habit of talking about it as if it was just a few miles down the road, and the characters were known to him personally. He tells me, almost apologetically, that the main town – Onomatopoeia – "is a bit of a building site at the moment".

We are talking in the room given over to the marketplace "which sits on the Avenue of the Gods, which leads to the Plane of the Gods, which is next door". He jerks a thumb towards the next room of the gallery. There, the model figures of the gods are in an undigified cluster on the floor awaiting placement on the Plane: Wi, the giant swimmer, clutching his rolled up towel, the tiny top-hatted, duck-beaked figure of Mr Impossible.

As we talk, we are eyed by a taxidermy model of a creature that has the snout of a pig, the body of a badger and the tail of an armadillo, and is trying to reach inside a jar to capture a pickled egg. (Pickled eggs are important on the Island, there are several jars displayed on a nearby plinth).

In the further room is a "ridable", a larger animal somewhere between a wolfhound and a llama. The human characters are "drawn from my imagination, with the odd exception of a cameo role for a friend, or an intellectual superstar". His wife gets to put in an appearance, as does Bertrand Russell.

Perhaps not surprisingly, comparisons have been made with Mervyn Peake, the creator of the Gormenghast stories, and with Tolkien, which Avery says "sends a shiver down his spine". He's more comfortable with allusions to Borges, Blake and Jonathan Swift. The Island more an eccentric offshoot of Mull than Middle Earth.

"I don't want to it to look like sci-fi, or 'Hey, this is weird and wonderful!' I sometimes think, have the people who say these things actually looked? What is so weird about this place? There are a few weird animals, but nothing weirder than would turn up in Australia, they're just different, they're completely plausible. The Gods are a strange-looking bunch, but if you look at all the gods human beings have evoked I don't think they're particularly weirder."

Nor, he says, is it meant to be a satirical comment on the "real world", which was part of the intention behind invented worlds of writers such as Swift and Thomas More. "People have perceived some kind of satirical content to this, and there really isn't. I think maybe people have mistaken my ultra earnestness for cynicism. I don't see it that way."

The work he calls the "showstopper" is a couple of rooms away, the Eternity Chamber, a structure a little bigger than a telephone box where a combination of mirrors and geometric patterns make the inside look infinite. The installation team are referring to it as "the Tardis".

"You can't go in there, for health and safety reasons," says Avery. "That's not the gallery rules, that's the conceit. It would drive you mad. I've been in there a couple of times and you do think 'Hang on, where's the door?'" He says that confining his work to a single imagined world is anything but restrictive.

"Some people talk as if it's a prison I've created, but it's the opposite. It gives to freedom to explore the ideas I want to explore. I might have a drawing which is more about mathematical philosophy, and one which is more about people. If you create a space where you put the things you don't have to relate them intellectually, you relate them spatially. It's about turning that intellectual space into a physical space.

"The Island is not a parallel world, it's part of this world, therefore it is a fiction. I use the word 'fiction' very broadly. History is a fiction, art history is fiction. Maybe reality is the biggest fiction of all!"

Charles Avery: The Islanders – An Introduction is at the Scottish National Gallery of Modern Art, Edinburgh, 29 November until 15 February.

BACKGROUND: ISLANDS OF IDEAS

Thomas More

Utopia, 1516

STATESMAN and scholar Thomas More created the island of Utopia (literally "No-place") describing it through the eyes of a traveller who observes its social, religious and political practices. Private property does not exist on the island and religious tolerance is paramount. For More it was both a place to explore ideas and a commentary on the times in which he lived.

Jonathan Swift

Gulliver's Travels, 1726

SWIFT'S book of fantastical travels was immensely popular in the 18th century, both as a great piece of storytelling and as a biting satire on the society of the day.

Later, parts of the story, particularly the voyages to Lilliput and Brobdingnag, were bowdlerised as a children's story, but the adult version remains a dark and intriguing classic.

Adolfo Bioy Casares

Morel's Invention, 1940

THE most famous novel by the Argentine writer and friend of Borges tells the story of a man on the run from the law, who discovers an island that is subject to mysterious repetitions. He later discovers it is a machine devised by a man called Morel. The story is thought to be one of the inspirations behind the TV series Lost.

Umberto Eco

The Island of the Day Before, 1997

ECO's postmodern novel is the story of a 17th-century noble who survives a shipwreck only to be trapped on a deserted and somehow unmoving ship.

The device provides a springboard for Eco to delve into history, fantasy, dream, reality, and the philosophical questions both of the 17th century and of our own time.