For fashionable London folk, it is not that hard to be cool. In a city devoted to high-end trend, all you really need is the cash. I understand it’s also quite easy in club-friendly, perma-sunny Ibiza, although I’ve not been there myself. But what about the Cotswolds? The place certainly bristles with organic vegetables and happy chickens, but life still tends to run on the archaic lines dictated by countryside tradition circa 1950. Which means it’s impossible to eat lunch out after 2pm, everything is closed on Wednesday afternoons and nobody has heard of Diptyque candles.

Not that this has deterred Jade Jagger, the designer daughter of Mick and Bianca. She has brought her brand of cool to this idyllic corner of the English countryside, and is hoping well-heeled second-homers will want a slice. Along with her business partner, Tom Bartlett, she has been hired by the funky developers Yoo to design the interiors of a range of houses for the Lakes, a new resort near the pretty town of Lechlade.

With what will eventually be 160 wooden lakeside homes spread over 650 acres of countryside containing six flooded gravel pits, the Lakes is intended as an ultra-fashionable, family-orientated getaway - as the Hamptons are to New York, but with a bit of Swallows and Amazons thrown in.

“We were given the shell of the house and adapted it,” says Jagger, 36, fresh off a plane from Ibiza, where she lives for half the year (for the other half, she resides in London). Those buying in the complex, where prices start at £775,000 for northeast-facing properties or £1.2m for those facing south, canchoose from two patterns: a Philippe Starck-inspired interior by the Yoo Studio, or the slightly more bohemian one designed by Jagger and Bartlett.

The “Jade” house, which we are in, includes a double-height entrance hall, a TV snug, an open-plan work space upstairs and two sexy bathrooms. And an Aga. “Forgiving modernism” is what Jagger calls it. “I like modern furniture and clean floors, because I have loads of dogs and children, and I think you should be able to just wash the floor down,” she says. “But I don’t think out-and-out modernism is a practical way of living. In my view, hard-core modernism in interiors ages badly, because you always want it perfect and clean.”

As she leads me on a tour of the house, she describes how she sacrificed the space upstairs for a grand, high entrance, because she enjoys a “sense of theatre”. The kitchen has sliding doors, allowing it to shrink drastically in size. “Sometimes you can feel a bit lonely in a giant open-plan space. And I like pottering about in a small kitchen, watching TV on a little portable.” Odd for someone born into the heart of rock aristocracy, but maybe that’s how you feel when you have lived in a lot of hotels.

The notion of cellular living is continued in the tiny snug, which, with its long cushioned seats, would be the perfect sleepover room for two or three children. The focus of the sitting room is a wood-burning stove. With damask-covered sofas, and William Morris wallpaper in the hall, the overall effect is not wholly rock-star. “I know, some things are quite out of fashion, really,” Jagger remarks, confidently clacking upstairs in bright-pink wedges.

She has, however, gone to town on the bathrooms. One is rather chilly, chrome and ensuite, but the other is much more luxurious: black and pink, with a textured rubber floor and a serious amount of mirrors. Sadly, there is no pole-dancing gear – apparently a feature of the vast bathroom in her London home. “Not that I’ve ever actually used it,” she confesses. “The bathroom is where I chat with my children. It’s an intimate family space. You know, a place where you can cut their toenails and talk about what sort of day they’ve had in school. You can utterly relax in the bathroom. It’s the one place I can give back to myself.” She and Bartlett joined Yoo as creative directors four years ago, but the pair have worked together for the past 10, doing the interior of Jagger’s Ibiza home, luxury designs for the Maddox Street Hotel, in London, and Garrard stores in Japan, Los Angeles and New York. For Yoo, she has kitted out the Jade, a £46m block of flats in New York, and is shortly to apply her decorative skills to a project in Turkey.

“I was always driven by interiors, although for some reason fashion came first,” says Jagger, who was creative director for Garrard until 2006. She now runs her own events and fashion label, Jezebel. “It’s a bit confusing for people,” she says, “but I offer a lifestyle brand, ranging from a rose-petal necklace to wallpaper. It’s taken me some time to realise it, but this is what brand strategists teach you: an exploitation of one’s creativity.”

This is something her dad has been doing for decades. Yet she strongly implies that being the child of Mick (and his £225m fortune) may have been hindrance rather than springboard. “My father is so successful, there might have been an assumption that I would be spoilt,” she says. “Actually, I’m a total control freak, and I’ve been working since I was 17.”

She is careful, however, not to overdo the “working girl” thing. “People want to aspire to something glamorous,” she comments wryly. “They don’t want to imagine Jade Jagger in her Marigolds. I always look like I’m having a good time.”

The Lakes is undoubtedly building on the growing market for prepackaged holiday bliss that has been tapped into so successfully by Lower Mill Estate, a stone’s throw away near Cirencester. The creation of Jeremy Paxton, a champion water-skier turned publisher turned developer, it has 190 homes in 550 acres of pretty lakes and nature reserves; all being well, by 2017 there should be 577.

Like its rival, the Lakes offers a second home in a groomed, safe (in other words, gated) environment where chic country activities (ballooning, polo, angling) are on hand and there is no question of slumming it in a microwaveless kitchen without underfloor heating. Kids can camp in teepees, swim, ride on zip wires and cycle, and on-site luxuries include a concierge service and a spa.

If price is anything to go by, the Yoo project offers more perfect bliss. Its houses are more expensive than those at Lower Mill – where a basic 1,500 sq ft lakeside three-bedder is £450,000 – and it has a distinct “fragrance de sleb”. The brochure has glossy pictures of its famous “design experts”: Starck, who helped to create the Yoo brand with the developer John Hitchcox, and Jagger.

A few weeks ago, Jagger tested the comforts of the Lakes on a weekend with her daughters, Assisi Lola, 15, and Amba Isis, 12, her long-term boyfriend, Dan Williams, some friends and her dogs. “The girls grumbled about having to leave London at the weekend,” she says. “But we all went canoeing and it was a laugh. Particularly when one of my mates got a leak in his canoe. Apart from the fake food in the kitchen [it is a show home, remember], it was fine. I’ve lived in the country all my life, actually. City living feels quite alien.”

So far, 27 properties have been sold at the Lakes, all off-plan (the houses are constructed from prefabricated boards made in Slovenia, and take a fortnight to put up). It seems, however, that the target market, family-centred high earners, is not entirely sold on Jagger’s vision: of the 27, 19 are in the “Yoo studio” design and only eight the Jagger version. Why does she think this is? “Maybe it’s because I’ve sacrificed having a giant master bedroom upstairs,” she says straightforwardly. “And maybe modern women are freaked out by the Aga.” She shrugs. Maybe her taste in interiors is too Manhattan for the Cotswolds. After all, Andy Warhol, a friend of her mother’s, used to baby-sit when Jagger was growing up in New York in the 1980s.

“To me, this is quite bland,” she says, waving her hand around the bedroom. “But then I would never say I was totally mainstream. Artists tend to be ahead of their game. Maybe you have to temper your vision and commercialise it a bit if you want to stay with it for a while.”

Now if that isn’t a nugget of wisdom straight from Daddy’s knee, I don’t know what is.

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