Playwright Dermot Bolger sees himself as an outsider. 'I quite like standing at a peculiar angle to the universe,' he tells Peter Crawley

One August afternoon in the early 1990s, a performance of Dermot Bolger's play In High Germany finished up and the crew began to clear out of its cramped Edinburgh venue. There was one problem. Still sitting at the back of the room was a man in an Ireland soccer jersey, heaving with sobs, unable to leave. The show was about Irish emigrants whose diminishing connection to their nation lay only in following international games. "That was my life," the upset patron told the production's director and its performer. "That was my life."

Touched by his reaction, but feeling more than a little uncomfortable, the theatre-makers tried to change the subject. What other shows had the guy seen in the Fringe Festival, they asked. "What festival?" he replied. A construction worker who had wandered in from a building site across the road, he came to get a sandwich and stumbled into a play that moved him to tears.

"In some ways," says Dermot Bolger, laughing when he completes the story, "that's my ideal audience."

Throughout his career as a novelist, poet, and playwright, Bolger has resonated with the lives of the disenfranchised and dislocated, with those stories excluded from the grand march of the traditional Irish narrative.

It's there in his depiction of the suburban working class in his debut novel Night Shift (written when he worked in a Finglas metal welding factory, while also starting up the Raven Arts Press), in the affecting plight of the émigrés of In High Germany or in the Protestant family turning to communism in his most recent book, The Family on Paradise Pier.

In terms of the Irish theatre, though, despite having contributed 10 plays to it so far, he is unsure if he fits the mould. "There was often a certain dichotomy between the audience I wanted to reach and the audiences who actually go to theatre," he reflects, sitting in a snug corner of the Axis Centre, shortly after watching a rehearsal for his new play, The Townlands of Brazil.

He recalls his excitement when his first play, 1989's The Lament For Arthur Cleary, departed the safe haven of the Project Arts Centre for a tour of Clondalkin, Finglas and Tallaght; places, he recalls, "where there was no tradition of theatre, and you actually had to fight to get the respect of the audience. It wasn't automatically given," he says.

"If you have a play in the Abbey or the Peacock or the Gate, a certain reverential hush falls when the play begins, whereas if you do a play in a non-theatre environment, people come in and they put it up to you: 'C'mon. Tell me why I should be interested. Tell me why I should be engaged.' If you get their respect it becomes very, very real and very alive. Often, in a conventional theatre, the play is forgotten before people leave their seats."

Bolger himself almost left the theatre behind a few years ago, focusing on novels since the end of the 1990s, before a commission from the new Axis Arts Centre lured him back to the stage. Bolger, a fluent anecdotist with a knack for amusing associations, refers to the American songwriter Sammy Cahn, who, when asked which came first, the music or the lyrics, replied, "the phone call".

"If you're a creative writer," adds Bolger, "very often the phone call comes, and it's a great challenge to try and work within the definition of the project."

That phone call resulted in 2004's From These Green Heights, a drama that chartered the 40-year story of two families living in the Ballymun tower blocks, and which went on to win the Irish Times/ESB Theatre Award for best new play. The Townlands of Brazil now follows, again set in Ballymun and directed by Ray Yeates. It is, says Bolger, both "a sequel and a pre-sequel" to their first collaboration - "which is an idea I stole from The Godfather Part II."

Beginning in the rural townlands of Silogue and Belcurris in 1963, just before the towers begin construction, the play follows a young unmarried Irish girl who conceives a child and chooses emigration over the looming threat of a Magdalen laundry. When the play continues in 2006 (following a 40-year interval), the journey has been reversed as a young Polish girl tentatively establishes herself in "a gleaming New Jerusalem" amid the demolition of the towers.

Bolger, who grew up two miles from the area in Finglas, recalls watching these towers being built as a child, when Ballymun was still a shining promise of modernity; a fresh start for families relocated from the tenement slums of Dublin. As the years passed he witnessed the dream begin to tarnish, as the optimism of the 1960s ceded to the sullied reality of the 1970s and Ballymun became "a dumping ground for problem tenants". Beset by poverty, unemployment and a heroin epidemic, the community fought back.

"Part of rebuilding Ballymun is to build places like the Axis Arts Centre," says Bolger, "so there's a sense that people have something to belong to."

He is loathe to present himself as the voice of Ballymun, however. "From These Green Heights wasn't my story," he says. "It was the story of a lot of people I grew up with and the story of my generation."

The Townlands of Brazil, he admits, is not quite his story either, but in its theme of emigration and dislocation, the search for home in a strange land, it has a deeper personal significance. "The only reason I have an Irish accent," he says, "unlike the overwhelming majority of my extended family, is that my father was a sailor who emigrated twice a week for 44 years on one of those small Irish ships. Emigration was always part of my family's story - and every Irish family. Eighty per cent of Irish children born between 1921 and 1941 emigrated. And those people were written out of history.

"So in some ways the story of somebody leaving their home, leaving a rural place and having to go into an alien world, which is the first act of the play, is the story of lots of Irish families. And the second act of the play, where someone from Poland and someone from Moldova find themselves in an alien landscape and gradually begin to conceive of that place as home, is the other side of my story."

As a chronicler of the marginalised, Bolger has never subscribed to the idea of a unifying national narrative - something which, like history, he believes is written by the victors.

The Townlands may not be dramatically elegant in its injection of social history into personal stories. (On hearing that life will be lonely without her shamed daughter, for instance, Eileen's mother replies, apropos of nothing but clunky exposition, "the real loneliness will start when 3,000 tenement families land on our doorstep.") But in its echoes between the parallel stories of Irish and Polish exile - which Bolger, who rarely asserts strict borders between novels, poems and plays, refers to as "slant rhymes" - it offers something of a dramatic palimpsest, in which the new city is inscribed on the old one, and the changing face of the country emerges.

"I think that one of the things for me about Ballymun," says Bolger, "is that it's a chance to explore the whole nation." Given the accelerated rate of its construction and renewal - "it's like a speeded-up microcosm of Ireland. And the journey of this play is that we are all two generations from the bog. I've never set myself up to be a Dublin playwright. I've always felt a writer of the suburbs. My great great grandfather didn't contract nefarious social diseases from Molly Malone. I've always hated this notion about the 'true Dub'. A city is whoever lives in the city. If that is now a migrant worker, then once they live here they become part of the story."

It now falls to Axis to make them part of the audience. Bolger counts one of the principal successes of From These Green Heights as its power to attract people to the theatre who had never been before. This time, his ideal audience would be composed of Ballymun residents, theatre-goers from outside the area and members of new immigrant communities.

"Hopefully," he says, "in the next five to 10 years a Polish person in Ireland will write the great Irish-Polish play, which I cannot pretend to do. I can try and understand Poland, we can physically bring over a very talented Polish actress [ Julia Krynke] and have her play Irish roles and Polish roles so there's a cultural exchange going on there. But in the end, I can only be an outsider trying to invent a story that hasn't been told yet."

Bolger is more than comfortable with his outsider status though. Far more of his plays are now performed abroad than at home, many of them in translation, and while his radio plays are frequently broadcast on BBC Radio 4 they are seldom heard on RTÉ. As a playwright at least, he could consider himself a migrant worker.

"I think there's no harm sometimes to feel on the edge of things," he says, referring as much to the characters of his fictions and his ideal audience, as to himself. "If you're on the margins you can see a bigger picture. And I actually quite like standing at a peculiar angle to the universe."

The Townlands of Brazil opens in axis on Nov 22. See www.axis-ballymun.ie