"Ripe pears and honey dripping off old, dusty walnut" - this is the distinctive smell of London's Royal Court Theatre, recalled by the actress Sarah Miles. For decades the cramped, shambolic Victorian theatre on Sloane Square has held a special place in the hearts of performers, directors and audiences. Before it closed for renovation in 1996 it was variously described in the British press as "a dump", and as "Europe's most innovative theatre".
For some, perhaps, the ongoing battle with unsafe, uncomfortable, unhygienic conditions was part of the theatre's challenge; the notion that art has to emerge from great struggle has an abiding appeal. Four years and many headaches later, the reconstructed Royal Court, which reopened this week after a month's delay, should reassure anyone who fears that creativity might have been thrown out with the creaking seats and noisy plumbing. The listed 1880s building has been transformed by Haworth Tompkins Architects into a flexible, welcoming, modern theatre that retains many of its original elements. The visual effect is richly allusive: layers of history coexisting with contemporary design - as befits a theatre that introduced the work of Ibsen and Shaw to London audiences in the early 1900s and has been associated with political radicalism since the 1950s. John Osborne's Look Back In Anger was the first in a wave of new plays which, in various ways, championed artistic and political freedom, by writers such as Edward Bond, David Storey, David Hare, Christopher Hampton, Joe Orton, John Arden, Howard Barker and Caryl Churchill. The loyalty and passionate identification with the theatre which this pioneering tradition has inspired made the architects' task particularly challenging.
There were physical constraints too. There was little room for expansion on the site, which is flanked by a London Underground station on one side, and shops, cafes and an enormous sewerage channel on the others: the architects decided to expand downwards, excavating beneath the road and traffic island of Sloane Square to create the new bar and restaurant area. While this complex and expensive operation was underway the theatre migrated to the West End, where over the past few years it has enjoyed one of its most successful and prolific periods, premiering work by Sarah Kane, the young British playwright who committed suicide last year, Mark Ravenhill (Shopping and Fucking), Martin McDonagh (The Leenane Trilogy), Pinter (Ashes to Ashes), David Hare (Via Dolorosa) as well as Ayub Khan-Din's East is East, since made into a successful film by Irish director Damien O'Donnell and Rebecca Prichard's Yard Gal. And of course, Conor McPherson's The Weir, which is still playing at the Royal Court's West End base, the Duke of York theatre, while his latest play, Dublin Carol, with Brian Cox, Bronagh Gallagher and Andrew Scott, opened the rebuilt Sloane Square theatre on Thursday.
Three days before the re-opening, the softly lit stairways and corridors are buzzing, as staff are still getting used to the new spaces. In the midst of it all, the Court's artistic director, Ian Rickson, is unfazed, surrounded by flowers and posters from the theatre's glory days of the 1960s.
With the designation of European Theatre of the Year, a 45 per cent increase in its grant from the British Arts Council, and a building project that cost £26 million sterling - drawn from National Lottery funding, private fundraising, the Arts Council and the Jerwood Foundation - the Royal Court is under the spotlight: expectations are high. Ian Rickson shows no sign of nervousness. "I'm excited and proud, and feel genuinely confident," he says. "It's a privilege to have this superb building to work in, which is allusive, evocative and contemporary and will stimulate playwrights. I have high hopes of the work we are programming for the next few years."
Irish playwrights - Gary Mitchell, Marina Carr, McPherson and Gina Moxley - feature heavily on this list, and Rickson is directing McPherson's Dublin Carol himself. Speaking about the current appetite for Irish plays in London, he chooses his words carefully and is reluctant to generalise. He wants to debate the subject rather than make pronouncements.
"The Royal Court is known for its pioneering work with young playwrights, from all parts of the world. We are reactive to what's happening in the culture generally - even proactive. We are thrilled that so many Irish playwrights want to work with us. We haven't done all the initiating either; they have approached us in many cases.
"Of course, playwrights such as Martin McDonagh, McPherson and Gary Mitchell are presenting very different aspects of Ireland. What's appealing to London audiences about Irish writing is that it resonates, there is a relish for language that distinguishes it from the deliberately flat, colourless work of a British playwright such as, say, Sarah Kane. Writing by Sebastian Barry, Marina Carr and Conor McPherson has dynamism and poetic texture. There is also a confidence with storytelling, with stories within stories, and that is what we go to the theatre for."
Conceding that we also go the theatre for ideas and form, he says: "For me, The Weir felt formally inventive too.
"McPherson's new play, Dublin Carol uses poetic, idiomatic language that is highly sculpted and which hot-wires you into great feeling. The play journeys into dark regions of the characters' souls as they grapple with death, love and other issues. It has enormous psychological depth."
He acknowledges that the reception of a new Irish play is inevitably different in Britain, and that certain nuances, and in particular, irony, may be lost. "Yes, I do think there is a reverence for Irish playwrights among English audiences that you wouldn't find in Ireland. I'm sure there would be more laughter at Dublin Carol if it were performed in Dublin."
He draws attention to the Royal Court's international programme, which includes an annual summer school for international playwrights and has forged links with companies and playwrights from Uganda to Israel. "What's most important for the Royal Court is that we keep setting ourselves challenges and that we are intrepid in reflecting the diversity of the culture around us. It's important to programme plays no other theatre would produce in terms of their bravery, in either content or style - their clairvoyance. This theatre is oppositional in spirit."
There is, however, a danger that commitment to oppositional work could lead to the pursuit of sensationalism, of new writing that is shocking for its own sake, or gratuitously violent. Plays by Sarah Kane - Blasted, Cleansed and Crave - and by Mark Ravenhill hit the headlines for their disaffection and a despair that bordered on nihilism, and to an extent this is what the Royal Court has become identified with.
"That does concern me," Rickson says. "I abhor work that is cynical or self-consciously shocking. But there is a vein of writing that reflects the real despair and rage of young people - Sarah Kane's Blasted, for example: that play resonated with people all over Europe. But that is not necessarily nihilistic. A play such as Marina Carr's Portia Coughlan, for example, is full of despair, but the very act of dramatising it calls for a change, makes transformation possible. This is what theatre can do. Isn't it?"