FROM THE SIXTH FLOOR offices of Dell Publishing you can look right down into Kurt Vonnegut's backyard. And from Vonnegut's back-room study, he can look up at the publishing house which, just seven months after he writes them, will send his every word to a million eager readers.

Vonnegut's new novel is Jailbird, published this month, and it's always a relief to him when a book's finished and ready to go.

His novels are written and rewritten page by page. Look around Vonnegut's workroom and you'll fund stacks of page ones, done and redone until he's satisfied to move along with page two.

"There are swoopers, and then there are bashers like me," he ruefully admits. But all 246 pages of Jailbird were bashed out by February, and since then he's been playing around with everything from Broadway musicals to cartoons.

The musical was a happy surprise: two young writers did a book and lyrics from God Bless You, Mr. Rosewater, the comically cynical novel about riches and greed Vonnegut published back in 1965 when he himself was a struggling unknown. Like its literary ancestor, the play started small, in the 100-seat WPA Theater, an experimental try-out house just north of New York's Greenwich Village.

Critics loved it, and Vonnegut was asked to supervise the rewrites while its producer -- Kurt's young daughter Edie -- salaries the cast and began looking for a Broadway theater small enough to preserve the play's intimate character.

With luck Rosewater will reopen just as Jailbird reaches the stores, and Kurt Vonnegut will once again be the toast of New York, a situation he finds enjoyable, profitable and personally stimulating.

His face brightens when told he seems wedded to New York. Originally from Indianapolis by way of Schenectady and Cape Cod, he's lived here since 1970 when Happy Birth, Wanda June made its Broadway success. "There's an angry energy in the city," he says, which his constitutionally low-keyed nature needs. From his townhouse in the East Forties he can venture out for long walks amid the architectural marvels his father taught him to admire, and with so many writers and editors nearby he can feel for once like the member of a true community.

Vonnegut had been coming to New York for years, of course, to sell his books and stories. "But I never had any place to sit down," he says, grinning.

Still, in New York you're up more often than down, and Vonnegut has now excused himself to take a call from People magazine. No, he doesn't want to give an interview. "A good interview is very hard work, and so I usually don't do them," he explains. But if it's for the play, and stays on that subject, he'll comply.

Back on the couch, with the street noise from Second Avenue drifting up this otherwise quiet block, Vonnegut counts off the other proposals he's been "playing around" with. "Ralph Bakshi, the animator, called last week. He wants to do a feature cartoon of Breakfast of Champions, which would be lovely because we wouldn't have to hire actors."

Eyes sparkling, chuckling at his own joke, he talks about another old proposition, this time to adapt Dr. Jekyll and Mr Hyde, a la Dracula , to the Broadway stage.

"Have you looked at Robert Louis Stevenson's book lately?" he asks. "It's only 60 pages, the barest outline of a story." But the play might be the perfect melodrama to showcase Vonnegut's own spare and caustic style. Though staying uncommitted, he thinks he'll try a few scenes and improvise some dialogue, "playing at the typewriter" to see if anything comes out.

Meanwhile he's been up to Hartford, speaking at the 100th anniversary of Mark Twain's classic Victorian home, Nook Farm. The words will be printed in The Nation, Vonnegut confides, only because his publisher saved a copy. Dozens of other pieces over the years have been lost because Vonnegut "saves nothing." Between 1944 and 1968, for example, only three photographs of this important writer can be found, one of them his brother's Kodak Brownie snapshot at the Iowa City airport.

The most amusing and appealing invitation Vonnegut has received, which he turned down with great regret, was to address the International Society of Indexers in England. "I'm the only writer ever to feature one of their trade as a character," he laughs. His interest rekindled, Vonnegut ends his new novel with an index. "It reads like a poem," he says, "with all those different names and places from so many pages apart suddenly run together. It makes for great verbal play."

The book's index also underscores its social seriousness. The story of a Watergate ex-convict's return to the Communism of his radical youth -- because it reminds him of the principles of the Sermon on the Mount -- is a much heavier subject than Vonnegut has dealt with in recent years.

Jailbird's narrator is a Harward man named Walter F. Starbuck, and Vonnegut says the portrait of his earlier years was inspired by the late Powers Hapgood -- Harvard grad, labor reformer and organizer for the Congress of Industrial Organizations. (C.I.O.).

"Hapgood was from a wealthy family, brilliantly educated and a business genious," Vonnegut reports. "He made his family's cannery the best in America, then turned around and gave his workers the profits. His altruism and the promise that bright young Harvard men like him could do so much for his country impressed me a great deal." Hapgood offered the young Vonnegut a job in the C.I.O. after World War II, and was turned down. But his example stayed alive in Vonnegut's mind. "Happgood's story has been one of the two subjects I've felt compelled to write about," Vonnegut explains. The other was the Dresden firebombing of Slaughterhouse-Five.

The phone rings and Vonnegut is up again, for the third or fourth call this hour. Back on Cape Cod he led a quiet and professionally solitary life for 20 years, sending stories off to Collier's and The Saturday Evening Post, some days having no one but the mailman say hello.

His New York life is different, and Kurt Vonnegut loves it. As his last novel exclaimed, he's "Lonesome no more!"