Despite being from Ireland, I've always avoided writing about it, for two reasons. For a very small country, Ireland has produced an astonishing number of literary geniuses, and at some level I probably never felt, having left as a toddler, that I had the right to try and add my voice. That's part of it. But I also didn't want to write something that was the equivalent of the Irish theme pub. You find them all over the world. The idea of producing a novel that might replicate that type of ersatz really set my teeth on edge.

It is a terrible thing to want something you cannot have. It takes you over. I couldn't think straight because of it. There was no one else, I realized, whom I could possibly tell.

The role you've been ascribed in childhood can twist or break apart or seem outgrown, especially when you have your own family and begin to see your own childhood from a different angle. You remember. You reassess. I think that was the kernel of the novel for me. This idea that you change but that your family, the people you were born into, might find that change hard to accept. You no longer fit the mold you've always been ascribed. When the adult children in the book converge back on their small family home there's a sense that they don't fit there anymore.

I was interested in the ripples of feminism passing through Britain and Ireland in the mid-Seventies - how the reverberations of the feminist political movement were being felt in suburban households. So many novels end with a marriage.

I think all families have these secrets, and it's sometimes the strangest things that bring them out. That was part of my interest in the heatwave, in heat as a catalyst for uncovering truths. I was reading Alice in Wonderland to one of my kids recently, and I remembered that it starts on a really hot day. Alice falls asleep because of the heat; the whole story is predicated on falling into a heat-fueled dream.

When my family moved from Ireland in the 70s, Britain was such a difficult place to be Irish. It was a decade of real social and economic upheaval in Britain. There were strikes, the three-day week, the oil crises, huge inflation, the winter of discontent and, what was it, four Prime Ministers? And relations between Britain and Ireland at that time were at an all-time low. I was born in the year of Bloody Sunday and of course the pub bombings happened in the mid-1970s.

I always had the urge to write. Not in the sense of wanting to be a writer, but just writing things down, getting words on a page. Graphomania, it's called. I've always had a definite love of stationary products - I used to spend all my pocket-money on pens and notepads. I still do, in a way.