"I think that's the guy who sold me my flat," says Will Adamsdale, peering through the window of Foxtons in Angel, north London. It's a fitting place to start, as it turns out. The comedian/actor/theatremaker – he still doesn't know which he is, "but that can be quite a liberating thing not to know" – has written a new play about buying a house.
In The Victorian in the Wall, he plays a writer and chronic procrastinator who finally moves in with his girlfriend and is faced with the tricky question of what comes next: marriage, baby, or – bingo! – home improvement. "They're in a bit of a rut and to feel like they're moving on in their relationship, they decide to get a knock-through. In lieu of thinking about anything scarier."
What begins as a satire on middle-class problems – too many box sets, festival fatigue, latte overload – takes a swerve into the surreal when the hero knocks through the wall and finds a Victorian man living inside it. "Period features: that's the thing that everyone wants when they go to the estate agent, isn't it?" reasons Adamsdale. "But they're old houses, not built for modern living. So then you have to rejig them."
Adamsdale – polite, diffident, lightly harried – worries about these things. His shows niggle, hilariously, at modern life. His heroes, 21st-century descendants of those of Ionesco, Kafka and Gogol, embody the futility of Modern Man. Take his absurd Perrier Award-winning creation Chris John Jackson, "one of the only guys in the self-help industry who doesn't claim to be able to help anyone", for example. Or the office drone in The Receipt, who risks everything on an impossible mission to find the owner of a piece of litter and ends up living in a storage container. Or the technophobe in The Human Computer who tries to build a PC out of cardboard and wax.
Is The Victorian his most autobiographical piece yet? "It's like a magpie, taking stuff from all over. It's not really possible to answer which bits are autobiographical and which aren't." Let's just say, there are some parallels. Adamsdale, 39, a "lazy writer" (his words), bought his first house a couple of years ago, and moved in to it with his then girlfriend, now wife, Maisie. They decided to "knock through" and found an ancient newspaper stuffed in the wall. Some months later, a play was born.
The show arrives at the Royal Court this week after a five-week tour. Adamsdale has appeared at the theatre once before, on his Jackson's Way revival tour in 2011. This time, he pitches up at Sloane Square for a month with a cast of five, including his long-time collaborator, the composer Chris Branch, a set of songs and Posh director Lyndsey Turner who has brought, he says, a "much-needed rigour" to rehearsals. "It's like we know we're in the same family but we're distant cousins. We all met doing shows at Battersea Arts Centre, over the river. But one thing they now want at the Royal Court is stuff that is a bit irreverent with the form."
He describes his approach as being "like a kid, playing" and is most interested in the "mesh" where comedy and theatre meet. It has led him down a peculiar path over the years. "You know when you go to a hotel and it says 'Profession' on the form? I've never been able to put writer. I think of myself as an actor more. But I just like getting in amongst it, doing what seems exciting."
He was born in Barnes and while still at Eton, he formed a theatre company, Double Edge, to take shows up to the Edinburgh Fringe, with friends Charlie Wood (now co-director of Underbelly), Oliver Dimsdale (co-artistic director of Filter) and Stephen Brown (playwright). After studying English and American literature at Manchester University – his favourite writer is Richard Brautigan – he enrolled at the Oxford School of Drama. "On my first day, I was late, wandering around Oxford trying to buy a leotard. I thought, 'Come on, how serious can this be?' But drama school taught me that you need to be on time. And that it's a very serious thing to be in plays." From there he spent five years in the theatre, playing "non-poshos" as often as he could. He still acts for others on and off, most recently in Detroit at the National last year and the films Four Lions and The Boat That Rocked.
A decade ago, he became a comedian "by mistake", thanks to Jackson, his American motivational speaker whose philosophy revolves around the power of pointless actions – trying to put your hand in two places at once, say, or to rhyme orange with leg. He took the show up to the Fringe "on spec" in 2004, was lionised by Stewart Lee and came away with the top prize. Typically, he then turned down all panel shows and offers to make Jackson into a radio serial or a sitcom that followed, and went travelling instead. "I got a lot of interest but I was a weird fit. People would say, 'What are you, exactly?' And I couldn't really answer that question."
Jackson lives on in any case. His parade of junkyard props is still lovingly stored beneath BAC ready for a return, possibly in documentary form. And might Adamsdale's next theatre show see him tackling fatherhood? He met Maisie, an actress-turned-teacher and daughter of Nick Dimbleby (brother of David and Jonathan) on the Tube. They married last year. "So she isn't a Dimbleby anymore," he says. "I think that's quite a relief for her, actually."
As for Adamsdale, he has found a new name for himself, too. After the interview he sends a triumphant postscript. "I've been thinking about those questions of comedy/theatre/writing and I think what's most important in all of this is the show… That's what I'll start putting on hotel forms – 'Show Guy'." It's a good fit.
'The Victorian in the Wall', Royal Court Theatre, London SW1 (020 7565 5000; royalcourttheatre.com) to 8 June