Hold the tartan! This new look scores a hole in one

Is it possible to be intimidated by bricks and mortar? It is when they form the shape of Gleneagles Hotel, the grand old lady of the Scottish Highlands. I was almost shaking in my shoes as I approached the entrance, and not just because of the grandeur of this faux French chateau; I was also a little nervous of the guests I might find inside, cobwebbed to the furniture.

"It might have been stuffy back in the 1920s, when it opened, but not now," explained Simon Brown, the hotel's PR manager, later, over a shortbread. "We want to draw on the hotel's heritage but provide what people need today." A quick glance about us in the main bar, where afternoon tea was in full swing, seemed to prove his point. My fellow guests bridged the generations – there were plenty of children – and most looked unlikely to have the means to casually snap up the £25,000 Rolex my partner had eyed in the window of the Mappin & Webb concession next to reception.

"But why would Gleneagles want you to come and write about them?" My mother had asked on hearing about the assignment. "It's a very good hotel, isn't it?" Apart from the fact that such a question ignores the essential dynamics of time and taste, she had a point. In most people's minds, Gleneagles is probably only matched by the Ritz, Savoy and Dorchester hotels in London as a standard-setter for top-notch hospitality. Does it really need to do anything to assert its stellar position?

Apparently it does. Parent company Diageo, the drinks giant, is lavishing £18m on a rolling programme of refurbishment to upgrade Gleneagles' facilities, bedrooms and communal areas and overhaul its famous golf courses. You might imagine that such a venerable hotel is so constantly primped and preened that it only needs a lick of paint here and a buff of the brass there to keep up to the quality mark. Yet, since the Chinook helicopters whirred away over the Ochil Hills, after the leaders of the G8 departed the hotel following their summit in 2005, Gleneagles has focused on its less-contentious forthcoming role as a host of the Ryder Cup, which comes to Scotland in 2014.

And, yes, Gleneagles is currently welcoming the press through its doors, keen to show off the latest of these improvements, a new Espa spa. I am offered a massage and advised to turn up an hour early to make the most of the new facilities, which comprise a steam room, sauna, two "lifestyle showers" offering chilly or tropical downpours and a psychedelic light show, with ice fountains for an extra pore-closing frisson, and a "vitality pool" with water jets, volcano chairs and a swan's neck for pounding knotted shoulders (cacophonous when, irresistibly, you turn them all on at once). By the time I reach the treatment room I am more than ready to submit, only resisting momentarily when I nearly kick the therapist in the face as she rouses me from my slumber by too forcefully tugging on a toe.

Had I fancied, I could have also indulged in a guilt-free lunch from the "spa menu", prepared in the kitchens of neighbouring Deseo, another just-completed refurbishment project. Deseo is the relaxed Mediterranean restaurant that offers the antithesis of the dining experience most would expect at Gleneagles, and has a novel "food market" where you can peruse the produce of the day before you plump for steak/turbot/ langoustine. There are more formal options to satisfy the traditionalists – the Michelin-starred eponymous showcase for chef Andrew Fairlie, and the hotel's signature restaurant, the Strathearn. But even the latter does not ask sir to wear a tie, and lets in children.

In fact, children are positively encouraged to visit the hotel. More quids have been spent on a new crèche and teenage club – one of the best I've come across due to its child-centred and creative approach. And these come on top of a leisure complex with two pools, and a mile-long list of junior activities, from falconry to off-road driving.

But the most fundamental change at Gleneagles is the re-modelling of its top storey into 10 premium suites, each of which has been afforded views of the glorious surrounding landscape – which was curiously not the case for the 33 bedrooms that previously occupied this floor. These "Spirit" suites most definitely do not fit the stereotype. "The Highlands" is interpreted through the decor with contemporary prints and textiles in the colours of heather, thistle, gorse and spruce, rather than garish tartans and trophies of dead wildlife. And, of course, there's hi-techery in abundance.

Ironically, the hotel's hottest feature hasn't cost it a penny and is rooted firmly in the past. Gleneagles was originally built as a railway hotel and has its own station, just down the road, served six times a week by the Caledonian Sleeper from London. Now, that will go down well with today's green-conscious customer.

COMPACT FACTS

How to get there

First ScotRail Caledonian Sleeper (08457 55 00 33; firstgroup.com /scotrail) calls at Gleneagles once a day, Sunday to Friday. Returns from Euston to Gleneagles start from £189, though Bargain Berths are sometimes available online from £19 single. Gleneagles (0800 704 705; gleneagles.com) offers a special rate of £385 per night for two, from Sunday to Thursday, May to October, with b&b in a Classic double and dinner in the Strathearn Restaurant. Europcar (0871 384 1089; europcar.com) offers car rental from £22 per day.