The house is forbidding: high wall, gate with bell. But the security, I realise as I enter, is less to keep other people out than small people in, as witnessed by the gaudy wooden structure that dominates the front garden: a fine new Wendy House.
Its owner is a solemn three-year-old with long, conker-brown hair. Indoors, while I wait for her daddy, she busies herself by tidying the cushions and her gentle-voiced mother, the writer Isabel Fonseca, goes to tell her husband I've arrived. The room is large, light and sparsely furnished, just a few paintings, several signed Fonseca (father, brother) plus two walls lined with books.
After a lifetime's state of siege, Martin Amis has decided to lower the drawbridge on the family fortress with the publication of his autobiography, Experience. His motive, he writes, was to set the record straight, in relation to both himself and his father Kingsley, following years of misrepresentation from a hostile press.
The impetus was an 18 months that saw the end of his first marriage, the death of his father, removal of a potentially cancerous growth from his lower jaw (together with all his teeth), meeting for the first time the daughter unwittingly conceived when he was 23 and the disinterment from the cellar in Cromwell Road, Gloucester, of the remains of his cousin Lucy Partington who had disappeared 20 years earlier, victim of mass-murderer Frederick West. On the professional front, there was the infamous split with his agent of 20 years, who is married to his until-then best friend, Julian Barnes. It was, he says, a pivotal time. And the writing of the book "was like a crash-course in concentrated mourning".
Amis, the subversive seer who excavated the substratum of Thatcher's Britain and distilled yob-speak into urban poetry, turns out to be a sensitive chap, loving husband, father and son. This is no hiss-and-yell memoir, with author as hero and the rest as villains, but as honest as self-portrait as you're going to get this side of the grave. What happened to all the anger that has typified his writing until now? "The anger in the novels is not personal, it's anger at certain things about life and about society and about the ill luck that some people are saddled with right from the start. The unfairness of it. I've been very lucky in my life despite my share of pain, and everyone has that. And my mother, when she read it, said she was so pleased I was so un-messed up. I suppose these things are shaped early on. And in my civilian life, my non-writer life, I am pretty steady."
But steady is as steady does. In 1993, when his sons were nine and seven, Amis left them and their mother for Fonseca. He writes that he was fully aware that his actions would destroy their trust in love for ever. How could he do it, having been through the same thing himself? "It was the low point of the whole thing really, facing up to that. One tries to behave honourably and you don't deliberately do wrong, but the one area that is out of your hands is love and sex."
But isn't that like a bloke saying: "I couldn't help it, I was drunk?"
Amis laughs. "It's like a bloke saying: `I couldn't help it even though I wasn't drunk.' It's like if you're born gay. I mean, what are you going to do about that? In E. M. Forster's time they'd pack you off to a doctor. But now we accept it as a destiny. Character is destiny, but sexual character is even more that, I think, because you can work on your character, but there's not a lot you can do about your sexuality and your affections. You don't calculate it and suddenly it's irreversible."
In "opting for love" Amis lost the day-to-day contact with his children that he now so values in his new family and wants to "hang on to hugely".
"I still see a lot of the boys and always will. They're part of my life, but it's true that they were pretty small when I left home and they're not in the weave of my life the way they used to be. So I would do almost anything to avoid that happening again."
Experience, like life, is structured around the twin pivots of birth and death. Writing it, says Amis, was emotionally draining and remarkably different from anything he had done before. "It completely changed my metabolism in that I would find it really very difficult indeed to get out of bed in the morning. I'm not an early riser. But then even at 12.30 I would think to myself I would love nothing more than another three hours sleep now. I assumed, as one does at this age, that this was some terrible new thing.
"But I can now see that it was emotionally exhausting writing that book. And the unconscious was switched off. That sounds odd, but I'm sure it's true. Because your unconscious writes your novels for you and I wasn't writing a novel, I was writing a memoir. And as soon as it was done, I woke up at 9.30 a.m. again and I could feel my mind working. And I thought, the unconscious is plugged back in now and there's a novel to write. Let's get ticking."
Martin Amis is currently working on a "political memoir", a study of bolshevism, sparked by Reflections On A Ravaged Century by Robert Conquest, a close friend of his father's from Communist days. Then it's back to the novel he's been "tinkering with for a couple of years now", about the world of West Coast pornography. ("And I'm afraid the world I write about hasn't improved. Still some terrible people in it. Same crowd of horrors.")
Amis's ability to swim in the murky undercurrents of British and American society earns him few friends in the lit. crit. world, it would seem, but he has learnt to take negative reviews on the chin. It will be different with Experience, however.
"A bad review of your novel is attacking your talent, but a bad review of this - I can't say I've had one yet, but I certainly will - is attacking your integrity, really. And your character, so it's personal. "A lot of the other stuff is personal too, but pretends not to be." Martin Amis has been the target of attack since The Rachel Papers, published when he was 23. (Nepotism etc.) Yet even as Kingsley drifted into Old Bufferdom and Amis fils eclipsed even his own early promise, there has been no let up: pilloried for his "cosmetic" dental work, excoriated for breaking up his marriage. Last week the Daily Mail ran a highly personal attack that ran to two pages. He hasn't read it and won't. Nor is he simply the butt of the yellow press. Among the roll call of contemporary masters, as witnessed by the Booker, the name Martin Amis is missing. (Kingsley won in 1986 for The Old Devils).
Although Amis has rung up nine novels, he has won nothing since the Somerset Maugham Award for a first novel more than 25 years ago. Does it make him angry? Irritated? Or doesn't he care? "I do care. You do want anything that's going, in that way and you do think it might win you some readers and - perhaps this is a rationalisation - some novels bring people together and some novels cause ructions, and in the Booker prize (judges) you are dealing with four or five strong personalities who have all kinds of literary agendas as well." Unlike his friend Ian McEwan, Amis's books are "not harmonial, but divisive". "And my books do press these alarm bells. So that's how I explain it to myself," adding with a wry smile, "and you know, I'll probably pick up a couple of career awards." Does he secretly still fear what he feared as a young man - that what he actually had was "a powerfully facile anti-talent?"
"I don't think you can doubt your basic contribution at this age. You do, in the Great Hall, you can take a pasting if you wander in there. You're aware of weakness in particular novels: but I don't feel as potentially omnicompetent, as when I was 25 - but I am a much better writer. "As Kingsley said when I said: `What is your literary ambition?' and he said: `To make a niche in literature'. And he did say rather sweetly - and it's not in the book - we can be pretty satisfied because we are this unusual father/son team and we are both some good. He claimed not to give a bugger about posterity and he said: `I won't be around, no bloody use to me to be read when I'm dead.' But it would be some use to me, as a counterweight against mortality, I mean that's probably why we have children and we write to try and make a contribution in some form."
Experience, by Martin Amis and The Letters of Kingsley Amis, edited by Zachary Leader, are reviewed by John Banville on Weekend 8 today