There’s a whiteboard in Joss Stone’s kitchen with next month’s itinerary mapped out in blue marker. Tomorrow, the singer is off to Berlin and Cologne to promote her new album, before going to Uganda on charity business. Then comes a blue square that reads “Back to Devon”, next to a little smiley face. Stone beams when I point it out. “Yep! And if there’s a way, if I can make the flights work out, I’ll come home before then. You have to hang on to your days off like they’re gold dust.”

We’re an hour or so into hair and make-up, and most of our conversation so far has been Stone, 22, who has amassed a personal fortune of £8m, waxing lyrical about the shambles of a country pile she calls home. It’s not surprising. Since she was propelled into the international spotlight at 14, her life has been largely spent on the road. And, contrary to reports that she was living in Los Angeles, home has always been here, in Devon. “All my neighbours and the people who live down the valley — I know everybody in this valley — they’re all really nice and they’ve known me for ever, so they’re not, like, loopy. You know what I mean?”

What I think she means is that her profile in the UK has taken a bit of a nose dive in the past couple of years. Her last album, Introducing Joss Stone, released in 2007, didn’t do so well, and then there was an appearance at the Brits in the same year, when her new transatlantic accent seemed to rub the general public up very much the wrong way. For the record, she sounds every inch the well-brought-up country girl, but with the huskiness you’d expect with a singing voice such as hers.

With that backlash to contend with, it’s no wonder she has been hibernating. “I just like to be here,” she says, when I ask what she has been up to. “I like being in my own little world. I like the quiet and, oh my God, the stars. There’s so much space to be creative here, and you can think easily.”

But with a new album, Colour Me Free, to promote, the bubble must burst. When we arrived, Stone was studenty, in no make-up and a pair of tattered Uggs, shuffling out to say hello before offering tea and toast. Now her PA, Tasha, an old school friend, bustles about getting the wood-burning stove lit, and a good-looking boy called Danny appears to be on hand simply to roll Stone’s cigarettes. It’s a beautiful day; dew melts off overgrown shrubs, and the greenhouse, where she is growing tomatoes (“Weeds are such bastards”), glints in the low autumnal sunshine. When she steps outside for her close-up, Stone has been transformed into the wild-haired diva we are more familiar with.

“I’m trying to schedule all my promo to happen here,” she says, “here” being her old family home (with no less than seven vehicles parked out front, in various states of disrepair), which she bought from her parents two years ago and is in the process of renovating, during which time she has been holed up in one of the outbuildings (“It used to be a pig shed”). She lives alone with her two dogs (a rottweiler called Missy and a white ball of fluff called Dusty), five cats (“We found them abandoned by the side of the road”), a pair of goldfish and an extensive collection of crystals.

To say that Stone’s current digs are eccentric is an understatement. One wall has been painted with bright green waves (or are they flames?), the result of a late-night boozing session. There’s no television, no proper heating and, frankly, an air of squat party about the place. Those millions, it would appear, are all being ploughed into the renovation next door. Stone is overseeing the project, having enlisted the help of a local posse of lads, which seems to be her style. She recorded the new album in a week, waking up one morning and deciding that was what she wanted. “They tried to tell me it wasn’t possible, but I was, like, ‘Just tell me what you need and let’s see.’ ” Her powers of persuasion are strong. “When you make people feel as if they’re making something impossible happen, they want to help because it feels like magic. They’re, like, ‘How exciting to be part of this little mission she’s on.’ ”

Quite. Stone has been accused of diva behaviour before, and her impulsive, DIY approach can come across as hot-headed. When Danny is dispatched to pick up lunch, he is instructed to bring back “Lurpak! None of that I Can’t Believe It’s Not Butter stuff”. But her next instruction — “Oooh, and get some beers. Let’s all get pissed and have a really fun day” — suggests her bossiness is little more than youthful enthusiasm. She insists that her motivation as an artist is “to have fun and enjoy my life”. Which means doing what she wants, when she wants. She has sacked three managers, because, she says, “people are mean”, and there’s an element of rebellion in the resolutely unstarry way she has chosen to live.

“I never wanted to be a pop star,” she says. “I just wanted to sing. I didn’t want to do videos. I didn’t want to be seen at all, because it made me shit-scared.” But she has got used to it, and has also learnt that “even when you have no confidence, you have to be able to pretend you do”. Indeed, there is an air of bravado in everything Stone does, including the overhauling of her family home. But her natural shyness comes across when I ask if Danny is the same Danny she has been linked to in the tabloids. She says yes, “but only because he drove me up to London to see Chuck Berry”. She wants lots of kids, but says that “I don’t f***ing know” who a good father might be.

Plans, meanwhile, involve “going back to college to study to be a midwife”, and filling the field next to her house with “cherry trees to supply the village”. At the end of the day, with a beer in one hand and a rollie in the other, she says she sees a “light at the end of the tunnel, and it’s a light from Devon. It will be nice to have a life where I go to work in the morning and come home at night. With that,” she points at the whiteboard, “you can’t really have a life”.

Colour Me Free is out now

Times recommends

• Second homes: credit crunch casualty or money-spinner?
• How I built my own sliding house
• Top 10 incentives for house buyers