Verdant green fields and a streaming river give way to houses of golden Cotswold stone, glowing photogenically as their owners, busy with village life, are rudely interrupted by an unexpected death. The forthcoming BBC/HBO adaptation of JK Rowling’s bestseller for adults, The Casual Vacancy, has a definite ring of Midsomer Mugglemarch about it.

Rowling’s study of life in a small English town dominated by small-minded folk seemingly determined to exclude poor people from their perfectly-kept streets was published to decidedly mixed reviews – but perhaps makes for better viewing than it did reading.

Adapted by Sarah Phelps, the plot is streamlined into three hours of television – the mini-series will be broadcast in weekly one-hour chunks from February 15 in the UK, and this spring in the US – and the inhabitants of perfect English village Pagford, at times quite unremittingly awful on the page, are rendered more bearable.

Phelps’ storytelling is assisted by some excellent casting including Michael Gambon (who has a prior association with Rowling’s work through his performances as Dumbledore in the later Harry Potter films) as power-hungry parish-council chairman Howard Mollison. His wife, Shirley, is portrayed with wicked, joyful malice by Miss Marple actor Julia McKenzie, while Keeley Hawes, much admired for her performance in BBC2 drama Line of Duty, plays against type as their brilliantly frustrated daughter-in-law, lingerie-shop owner, Samantha.

Rowling’s book can be quite relentlessly bleak. Phelps has also injected more humour and, by allowing The Casual Vacancy’s hero to survive for longer than the scant few pages Rowling permitted in the novel, brought some much-needed warmth to the screen.

A boundary line dispute – not the most televisual of arguments – has become a tussle over the conversion of a community centre into a “wellness spa” in a story that confronts changing attitudes towards redistribution of wealth and those living in poverty. The story of teenager, Krystal Weedon, struggling to manage an addict mother and look after a baby brother, is at the heart of the adaptation. Nodding to a dramatic vision that sees echoes of 19th-century fiction in Rowling’s tale of Pagford’s residents, Phelps described the apparently tough girl as Tess of the d’Urbervilles.

The author was relaxed about her work being adapted, Phelps said at a London screening of the drama earlier this week, admitting that the process could potentially have been very difficult. “There was a great deal of freedom for me. [Rowling] read the scripts that came in and commented appropriately.” Any tough notes? “No not at all. She’s a writer, she understands what that’s like.”

But not all the real-life residents of the half-a-dozen Cotswold villages that together created picturesque Pagford were quite so understanding. Samantha’s lingerie boutique, with its racy window-displays, resulted in complaints to the council. (Others, however, were apparently disappointed at its fictional nature, heading inside to rummage through the red-satin corsets. “We had a couple of old ladies, white hair, stick, walking past and looking in the window,” said director Jonny Campbell. “We were saying: ‘Please excuse us.’ [They said] ‘Oh no, I’ve got all that stuff at home.’”)

Pagford’s timeless good looks are underlined by the blessing of a balmy English summer. And in terms of British village life translating to American audiences, who also bought the book in droves, it is hoped that the relationships and stories will prove universal. “You’re just watching people’s behaviour, marriages, relationships, and how hard it is to stay sane in one of those tiny little places,” said Phelps. “They’re beautiful these villages, but I’ve got to say if I lived in one I’d run amok.”