FOR 15 years it has been all about Hogwarts but now JK Rowling, the author of the massively successful Harry Potter books, is to introduce us to a new place: Pagford.

Publishers Little, Brown announced yesterday Rowling's new book – her first for adults – will be called The Casual Vacancy and will be set in an English village called Pagford.

Little, Brown had already revealed in February that Rowling was writing the book following the end of the series of Harry Potter novels, which have sold 450 million copies, but yesterday the title, details of the plot and the setting were all revealed.

Pagford is a perfect English village with an abbey and a cobbled square but, as you might expect, there is a twist. It is, says the publisher, not what it seems. Whether it is inspired by the place where Rowling was born, Chipping Sodbury near Bristol, is not yet known.

The book starts with a character called Barry Fairweather, whose death leaves a space on the parish council. This causes a huge war to break out in the village, with rich against poor, teenagers against parents and teachers against pupils.

After the fantastical setting of the Potter books, which have earned 46-year-old Rowling an estimated income of £620 million, an English village might seem a little Midsomer Murders, but her publishers said the book was constantly surprising, thought-provoking and blackly comic.

Waterstones said it also expected the book to be a big hit, which might just come at the right time with paperback sales falling at the expense of a rise in the sale of ebooks. Spokesman Jon Howells said: "It will obviously be a major bestseller, probably the best-selling fiction title this year."

Mr Howells said it was a real surprise Rowling had decided to reveal so much of the plot ahead of the publication date having surrounded the Potter books with secrecy for so long.

"The plot sounds like it will have hints of Mark Haddon and [Alexander] McCall Smith, and the promise of black comedy is very beguiling," he said.

The Casual Vacancy, which is 480 pages long, will be published around the world on September 27 as a hardback, ebook and an audio book. Amazon made it available for pre-order for the first time yesterday.

Rowling has not said much about the book as yet but she has tweeted it will be very different from Harry Potter. "I've enjoyed writing it every bit as much," she said.

When plans for the book were announced, it was also revealed Rowling would be moving from Bloomsbury, which published all the Potter books, to Little, Brown. She said: "The freedom to explore new territory is a gift Harry's success has brought me, and with that new territory it seemed a logical progression to have a new publisher."