The institutions that take care of our elderly population — which run the gamut from the grimmest of nursing homes to the relative dignity (and expense) of assisted living — share certain characteristics with high school. There’s the forced proximity among people who might not otherwise have much to do with one another, and the way time is both regimented and aimless.

But while adolescence is a classic subject of the novel, old age is not. Only a few novels that are really and seriously about it come to mind: Elizabeth Taylor’s “Mrs. Palfrey at the Claremont,” Barbara Pym’s “Quartet in Autumn,” Marilynne Robinson’s “Gilead,” Alice Thomas Ellis’s “The Skeleton in the Cupboard” and Barbara Comyns’s “The House of Dolls.” To this list, we can add books by the Swedish-speaking Finnish artist Tove Jansson. Her novel “The Summer Book” (1972) followed a woman watching over her tempestuous granddaughter, and “Sun City” (1974), set among retirement communities in Florida, has just been reissued by New York Review Books Classics.

“Sun City” by Tove Jansson, translated from Swedish by Thomas Teal. New York Review Books, 214 pages. Paperback, $16.95

At the Berkeley Arms, a boardinghouse in the “sun city” of St. Petersburg, Florida, women with fluffy white hair (and the occasional bald man) do their best to make use of their final acts. Their best is not always adequate to the occasion. To one resident, the Berkeley Arms does not resemble high school but something even more juvenile: “I live in a kindergarten,” she reflects. “No one realizes how much cruelty there is in a kindergarten.”

These are prickly and opaque characters. There is Elizabeth Morris, 77, who avoids revealing anything about herself. And the cringingly nice Evelyn Peabody, 74, skilled at “[hiding] what was worn and poorly made and [emphasizing] what was pretty.” Evelyn lives in dread of the abrasive Alexander Thompson (who, at 80, “has survived a good deal longer than he ought”) and the aloof Rebecca Rubinstein, 81, who writes long letters to her son and then destroys them unsent. Even the owner of the Berkeley Arms, Miss Ruthermer-Berkeley, is old: 93.

Though tiny, birdlike Ruthermer-Berkeley rarely mingles with the other residents, she is the book’s presiding spirit, and the contentment and freedom that she has found, we’re told, only after 90 is its gentle provocation:

“Without sense or consideration she had striven for perfection and thus had lived with constant anxiety, anxiety for everything left incomplete the day before — work, duties, conversations — and anxiety for the day to come, which had to be shaped to suit her wishes and the demands she made on herself. Lost in the future and the past, she had not been able to live in her own moment. It was really a great shame, an omission that had probably made no one happy. But now they were all dead, and there was hardly time to mourn mistakes that were as old and as silly as that.”

“Sun City” is not a story in which we see old ladies get their groove back, but one in which Jansson tries to envision what a good life might look like in these circumstances, in an artificial community whose sole purpose is to give you a place to wait out the time you have left.

The novel also includes younger people — Linda, the cleaner at the Berkeley Arms, and Bounty Joe, her motorcycle-driving boyfriend. Bounty Joe is convinced that the end of the world is nigh, and he lives constantly anticipating a letter from “the Jesus people” summoning him to the location where he will await the second coming of Christ. To a resident of one of the retirement homes, who is worried that Bounty Joe is squandering his youth, he says there’s nothing to squander if the world is ending. Much like all the elderly people he helps to care for, Bounty Joe’s sense of a limitless present is formed by his conviction that there is no future.

Jansson is best known for her Moomintroll comics, but those who have come to love her fiction for its gentle, if often pessimistic, humanism and her attention to the tactile and natural world will find those traits in “Sun City.” Center stage in this novel is her interest in old age as a distinct phase of life, not only as decline — though, of course, there is decline. Even the young people of this book aren’t exactly young.

But the novel also suffers in comparison to Jansson’s other books. Her focus on a panorama of the elderly is quite different from her other fiction, which often involves a smaller cast of characters — sometimes only two people — who are often physically isolated from the wider world. Ultimately, the book suffers under the weight of this ambition. The relationship between two or three people on an island exists within strict conditions: No matter how volatile, intimate or cruel, the players are fixed. When you can simply walk away from one tedious companion to find another you like better, it’s not the same, even if you’re still stuck in the same boardinghouse together.

In Jansson’s short story “Black-White,” an artist withdraws into a decrepit, empty old house to experience true darkness. Sketching the sitting room, he imagines writing to his wife of drawing “nothing but the walls and floor, a worn plush carpet, and a wall panel with a repeating pattern. It’s a picture of the footsteps that passed through the room, of the shadows that fell on the wall, of the words that still hang in the air — or maybe of the silence.” Capturing that silence that hangs in the air is Jansson’s most remarkable writerly gift, but in “Sun City,” she makes only light use of it. Second-rate Jansson is better than most writers’ best, to be sure. But there’s a lot of first-rate Jansson out there: If you haven’t read any yet, don’t start here.

B.D. McClay is a critic and essayist whose work has appeared in the New Yorker and Lapham’s Quarterly, among other publications.