With a Hollywood star for a wife and an Academy Award for a doorstop, Sam Mendes has moved on since the days when he ambled down the Royal Mile handing out flyers for his own Fringe show. In a decade of film-making, the Reading-born director has worked with Paul Newman, Tom Hanks, Kevin Spacey, Jude Law and Jake Gyllenhaal, and won an Oscar for his feature debut, American Beauty. His wife is award-winning English actress Kate Winslet, who starred opposite Leonardo DiCaprio in 1997 blockbuster Titanic and was paired with him again in Mendes’s most recent film, Revolutionary Road. And home is an apartment in New York’s Greenwich Village, though there’s also a £3 million manor house in the Cotswolds set in 22 acres.

It’s no wonder, then, that Mendes looks pleased with himself when we meet – though in fairness, I think it’s natural ebullience rather than smugness that’s working his smile. The grizzled grey beard just adds to the air of gnomic bonhomie.

The theatrical wunderkind who brought a student production of Samuel Beckett’s Endgame to the Scottish capital in 1986 is still in touch with his dramatic roots, even if the stages and the stars are a little bigger these days. The 44-year-old is currently involved in The Bridge Project, an ambitious scheme to mount classical productions in both London and New York using Anglo-American casts. The Cherry Orchard and The Winter’s Tale have just closed the Project’s first season, and in January Anne-Marie Duff is among the cast of British actors heading to America to appear in As You Like It and The Tempest.

But before that there’s another film to come, shot while Revolutionary Road was still being finished and in some ways its counterpoint. Away We Go was written by novelist Dave Eggers and his wife, Vendela Vida, and opened this year’s Edinburgh International Film Festival. It stars John Krasinski and Saturday Night Live comedienne Maya Rudolph as Burt and Verona, a slacker couple expecting their first baby who travel the US looking for the perfect place to raise their child. It’s fond and funny and, without giving too much away, the journey they make ends up being circular. There’s a star turn from Maggie Gyllenhaal as a controlling earth mother with some strange ideas about child-rearing, but it’s Rudolph and Krasinski who dominate and who most impress.

After serious films like Revolutionary Road, a portrait of a marriage in meltdown based on Richard Yates’s 1961 novel, and Jarhead, set during the first Gulf War, Away We Go has been seen as a departure for Mendes. The director doesn’t entirely agree. “People say: ‘Oh, you’ve made your first comedy,’ but I thought I was making a comedy when I made American Beauty,” he tells me. “All my films are linked by similar concerns, if you look below the surface. They’re all about one or more people who are lost and trying to find a way through. It’s no different with this one, it just happens that they do find a way through.”

He does admit, though, that this is a film he wouldn’t have even considered doing a few years ago. “It wouldn’t have chimed with me in any way. I didn’t have kids, I didn’t have a wife. Those things didn’t interest me at that time.”

And how is Mrs Mendes? “She’s great,” he laughs. “She’s at home looking after the kids and looking for something to focus on next. Someone, somewhere is writing something – and that will be the next six months of her life next year.”

That “someone, somewhere” looks like being director Todd Haynes, currently turning James M Cain’s novel Mildred Pierce into a mini-series for television. It would mark a significant change of direction for Winslet after a year in which she won a Golden Globe for Revolutionary Road and an Oscar for her performance in The Reader, directed by another British dramaturg, Stephen Daldry. But, as her husband says, “it’s all so random”. You never can tell in this business.

One thing that is constant and unchanging is Mendes’s choice of cinematic location: America. In American Beauty he mined the country’s suburban underbelly; in Jarhead, its military misadventures; in Revolutionary Road, its literature; and in Road to Perdition – an adaptation of a graphic novel set in the 1930s – its

mythical gangster past.

“I am fascinated by America, no question about that,” he says. “I will stop making films about it eventually, though, because I think there’s a limited amount to say. But I am drawn to it.”

Fittingly, the film which inspired him most directly as a young man was Paris, Texas, shot in the US in the early 1980s by German auteur Wim Wenders. Mendes also talks about three other non-American film-makers who have made America their subject and whose work has influenced him: Alfred Hitchcock, Ernst Lubitsch and Ang Lee.

And then there’s Billy Wilder. “He spoke with an Austrian accent until the day he died but made an amazing array of American films,” he says. “These are all film-makers I admire, so I don’t think it’s weird at all for an outsider to go and make movies that are quintessentially American. I think the 20th century shows that there is a tradition of people being drawn to America as the site of the great mythic landscape. You can tell big stories there that you might not be able to tell with such scale and grace elsewhere.”

Reading, for instance, where both he and Winslet were born 10 years apart. Or even London, where Mendes cut his teeth at the Royal National Theatre directing plays by Harold Pinter and Edward Bond in the late 1980s. He may one day make a film set in Britain, he says, but it won’t be this year or next. He is currently developing a costume drama, an adaptation of George Eliot’s 1871 novel Middlemarch, but it’s some way down his to-do list. He’s also planning to produce a big-screen version of ITV hit Lost in Austen. Again, there’s no date set.

A third project his name has been linked to is another comic-book adaptation, Garth Ennis’s Preacher, but the film most likely to occupy him next is an adaptation of Joseph O’Neill’s novel Netherland. If it happens, he will make it from a script by playwright Christopher Hampton for Harpo Films, Oprah Winfrey’s production company. Still, at least the subject matter sees him edging closer to Britain, as it concerns a group of expats who meet regularly in New York to play cricket, a game Mendes loves.

You can take the boy out of Berkshire, it seems, but you can’t take Berkshire out of the boy.

Away We Go is released on September 18.