This new spa offers frazzled parents a little slice of Haven

My toes are still tingling from the loving attention lavished on them. "Deluxe", "Zenspa" ... I'll have the lot. After months of bad weather and thick boots, I want sexy sandal feet. Next up, a facial. As the therapy lights move through their rainbow repertoire, she barely touches my forehead and I drift off on a cloud of calm.

I'm at a Haven holiday park, grabbing a little me time before my children return from a gruelling timetable of trampolining, archery, quad-biking and aqua fun. My six-year-old son has long been harassing me for a Haven holiday, seduced by the brash TV ads. When the company announced it was unveiling a new Decléor spa at its Rockley Park site in Dorset, the idea suddenly seemed so much more attractive.

Clever Haven. It knows that families like mine exist in these credit-crunch, mustn't-go-abroad days and is taking the holiday-park experience upmarket to reel us in.

Building on the success of its first spa, which opened in 2004 at Devon Cliffs, near Exmouth, Rockley is the second site for this incongruously luxurious project.

Then again, Rockley is used to rubbing shoulders with the elite. It shares the same sought-after vistas of Poole Harbour as its neighbour, the millionaires' playground, Sandbanks. And those holidaymakers who have bought into the dream by purchasing their own homes here have come to expect special privileges, such as the dedicated swimming pool in a quiet corner of the park.

Now they can also enjoy the sight of the new spa from their lilos – it's set in £350,000 worth of landscaping by Neil Tulley Associates, who designed the gardens at Elton John's home in the south of France. And for the eco-conscious, David Bellamy has even given the park his stamp of approval with a suitably glittery Gold Conservation Award.

Back in the spa, the menu of Decléor, Jessica and St Tropez treatments is served up in a suite of four therapy rooms, with a spa garden offering hot and cold "wet experiences". To be honest, the treatment rooms are a little spartan and would benefit from warmer, more luxurious decor, as in its public areas. But the level of service is good and the value can't be faulted – choose a pedicure or a manicure, from £26, and you get to take home your choice of nail varnish, too.

Haven has such faith in its spa idea that it's due to open another at Haggerston Castle in Northumberland in a couple of years, to replace a tiny existing salon. It's all part of a commitment to "exceeding the expectations" of its regulars – and a way to hook in us cynics.

And that commitment is dead serious. Last winter, Haven spent £40m across its 35 parks, improving facilities, accommodation and landscaping.

Caravans have been reorganised into "low-density communities" with more space and better planting to improve views and lessen the environmental impact. Platinum and Prestige caravans have been introduced this year, offering more space and higher grades of accommodation, with extras such as flat-screen televisions. You can book your linen and even get the beds made up, though you must bring towels, toilet rolls and washing-up kit. This is a caravan, after all.

So forget Hi-de-Hi! – after a slip of the tongue I was reminded Haven is a holiday "park" not a "camp" – I was impressed. OK, the en-suite was cramped and I bashed my back on the three-way door on the bathroom cabinet, but I just hot-footed it back to the spa for a hot-stone massage.

In lean times, a little luxury goes a long way.

How to get there

A three-night weekend in a two-bedroom Superior caravan at Haven Rockley Park (0871 230 1900; haven.com) is available from £339. Children enjoy free swimming, kids' clubs, ranger walks and entertainment. Other activities (to be booked on arrival) include fencing and archery.