In The Studio: Mark Wallinger

"Those are aluminum foil balls scanned on the office scanner," says Mark Wallinger, pointing to the in-scale set of the ballet he has designed. In the middle of Wallinger's set rises a large mirror that will "reverse expectations". Metamorphosis: Titian 2012 is composed of three ballets by different artists. Part of the Cultural Olympiad, it will have its world premiere at the Royal Opera House in July.

We are in Wallinger's airy, newish studio – he dubs it the "romper room". Double-aspect, as an estate agent would say, it is a far cry from the small and, dare I say it, dingy Waterloo studio he was previously in. There is no sign of paint or the usual art materials here.

There are, however, eye-catching objects dotted around; a furry brown object on the windowsill reveals itself to be a bear mask – part, perhaps, of the bear costume that he donned in a Berlin art gallery. A blue plasticine Earth-like blob hangs on fishing wire. Nearby, on his large desk, is a commercial globe that Wallinger points out is a lunar globe. He is currently looking at objects that pertain to the moon, the theme of his impending National Gallery exhibition and ballet.

On the floor is a chess board with carefully arranged pebbles, a preparatory plan of his larger project at his upcoming Baltic show, a work that will include 65,536 pebbles. Wallinger's numbering works are all about systems, giving order to disorder. "Putting them on the squares changes their sensibility totally, giving each pebble a level of importance that a group on their own just does not possess," he explains.

Wallinger won the Turner Prize in 2007, having previously been nominated in 1995, when he lost out to Damien Hirst. Wallinger was part of the group of artists included in Sensation: Young British Artists from the Saatchi Collection in 1997.

He points out that he is slightly older than many of the rest, having been born in 1959. I say, "An Essex boy made good", and he responds defensively, "Essex is not all bad. It was 50 minutes by train into the city and we went with my mum to the ballet and theatre and exhibitions, and a block in the other direction there were fields and open spaces."

Its propinquity to open fields probably helped form his love of horses – horses being the subject of his first Turner prize entry, and his 2009 project to build a huge model of his own race horse near Ebbsfleet in Essex. The project hit the buffers in the economic downturn, but was universally liked by both press and punters. "It would have been 472 hands," he smiles.