Actress Jessica Stevenson has refreshed the sitcom, but wants more risks, she tells Imogen Edwards-Jones

Spaced, the Channel 4 sitcom that took the hackneyed format of people sharing a flat and turned it into something fresh and funny, is back for a second series on Channel 4.

In essence the series is about two feckless twentysomething flatmates, Tim and Daisy (played by the series' writers, Simon Pegg and Jessica Stevenson). But it's the way the show combines cartoon action and surreal comedy with a liberal sprinkling of pop cultural references that has earned it acclaim and a loyal, cultish audience.

"Simon and I had moments of worry about not being able to live up to the first series," admits Jessica Stevenson, a bright and garrulous 28-year-old. "And then we realised that we had plenty of ideas. In fact, it involved more reducing the ideas, editing them down, rather than worrying about what to do next. The first series was us dividing up the writing and editing each other's work in our own flats. The second series was us in an office with computers. It was quite a haphazard process.

"I did often think that it was a miracle the amount of work that we did, because all I remember doing is buying a lot furniture for the office from Ikea, having lunch at 11.30am and sleeping."

It's a working relationship that has clearly worked. Spaced now enjoys a devoted following that includes such celebrity fans as Kylie Minogue and Chrissie Hynde. The second series has also attracted some famous guests, including Sixth Sense star Olivia Williams, who not surprisingly turns up in a Sixth Sense spoof.

This series is also developing a will-they-won't-they element to the relationship between Daisy and Tim. "We both get a bit of sex in this series," says Stevenson with a smile. "But not with each other. It's very tragic. Tim gets some gorgeous and rather confident girl and actually has a bit of a relationship and Daisy gets a biker."

It's Daisy's inability to find a direction in her life that explains much of her appeal. "I know," agrees Stevenson. "Daisy is sort of deciding who she is and what she wants. She is not really clear about anything. She is not a very purposeful person."

The same could not be said of Stevenson. Born and brought up in Brighton, the youngest of two sisters, she left school after her A levels and headed for London to pursue an acting career rather than go to university. "I don't think that I was thick. I was just so clever I was bored," she says laughing. " That's why I was sitting at the back of the Maths lesson writing out Prince lyrics!"

A fervent member of her local Saturday morning drama club, and a member of the National Youth Theatre from the age of 14, Stevenson already had an agent by the time she arrived in the capital. "I was at that drama club come rain or shine," she says. "Doing Victoria Wood monologues, pretending to be Liverpudlian, standing at the bus stop, being pregnant. I loved it. And the youth theatre was a big blossoming thing for me. You know, snogging boys, drinking pints and getting to run around a big hall. I loved it all."

After playing bit parts, including "a very obvious Cockney secretary" in a training video, Stevenson was cast in the 1993 Disney film Swing Kids, filming for two months in Prague with Kenneth Branagh and Christian Bale. "It was a baptism of fire. It was quite difficult being away from home and I was on this massive, massive film set. I remember going to record the post-synching and some vile American saying: 'Now is the chance to save yourself.' They were ruthless people. It was a very odd atmosphere."

But Stevenson was determined to be taken seriously as an actress, delivering the Baby of Macon in Peter Greenaway's film, before moving on to the West Yorkshire Playhouse. However she didn't like the hanging around that came between jobs. "I didn't enjoy the powerlessness and the arbitrary nature of auditions. I didn't want to spend my life waitressing and going to auditions, without any idea where this was going. So I wrote a short film with my friend Katy Carmichael (who plays Daisy's girlfriend Twist in Spaced) and we started to do comedy."

A chance meeting with Simon Pegg at the auditions for Six Pair of Pants, a 1995 comedy show for Anglia TV, established their friendship. But it was her casting as Cheryl, the fish and chips-obsessed nervy neighbour in The Royle Family, that really established Stevenson as a comedy performer. She went on to win the Best Female Newcomer award at the 1999 ITV Comedy Awards.

"I remember meeting Caroline Aherne and Craig Cash for the first time and thinking that they were going to tell me they had made a terrible mistake in hiring me. But they didn't. It was my mum's 50th birthday and they wrapped up a can of baked beans and gave them to me to give to her. I thought that means I must have the part."

Stevenson, who is about to take on a non-comic role in the ITV drama Bob and Rose with Alan Davies, is now in a position where she can pick and choose her roles, but is keen to continue her writing.

"I want to improve my narrative skills as a writer and go where that takes me. I do have a tendency to be a bit serious, so I have to stop myself. But I am interested in diversity and working with people who are good. I would like to find out if I am good, to get someone to really take a risk on me."

Spaced is on Fridays on Channel 4