Emma Keelan.

Hotels have come a long way since the slabs of Bauhaus concrete of the 1950s. These days some of the most impressive modern buildings on the skyline are not art galleries or centres of commerce but hotels, from the imposing limestone-clad Four Seasons in New York to the elegant art-deco Grand Hyatt in Shanghai. And inside too, hotels really are chucking out the chintz. The ultra-modern, minimalist and above all individual designs of boutique hotels have revolutionised the way hoteliers think about kitting out their buildings. New hotels are no longer designed purely as places to sleep, and luxury is no longer judged on the quantity of velvet and gilt used in the decor, but rather on the imagination and style of the interiors.

'We wanted to do something new and different,' says interior designer Mary Fox-Linton, who in 1998, along with hotelier Gordon Campbell Gray, designed One Aldwych in London, the hotel widely credited with kicking off the boutique movement in the UK. 'I had worked in contemporary design for many years and it was something that was dear to my heart. We made a breakthrough and others started to follow on in their own way. Of course Phillippe Starke had already been designing hotels in the US, but there was nothing like that here.'

She adds: 'The timing was right. People had begun to look at modern buildings and realise they weren't so awful. Homes and offices were being designed in a contemporary way. Modern restaurants had started to open up, serving different kinds of food - not just the traditional Italian, Indian or French food. It was a whole movement. There was no reason for hotels to be stuck in a time warp.'

The hotel industry was doing well in the 1990s: revenues were up and more buildings were being opened. So there was the opportunity for change and the boutiques flourished. And it continues to hold its own despite 9/11, foot-and-mouth, SARs and last summer's terrorist attacks in London.

According to Mintel, there are an estimated 18.4m hotel rooms around the globe and this has been growing at roughly 3% over the past five years.

And PKF figures for the UK showed a 6.2% increase in occupancy to 86.7% between June 2005 and June 2006. 'The June figures continue to reflect the strength and dynamism of the UK hotel market as a whole and the dominance of London as a world-leading centre of business and tourism,' says Robert Barnard, partner for hotel consultancy services at PKF. 'A year on from the tragedy of the London bombings after which hotel occupancy figures plunged, the comeback clearly demonstrates both the resilience of hoteliers and the timeless appeal of the capital as a global destination.'

So, almost a decade on, hotel design continues to evolve. 'Interior design has progressed a lot,' says Fox-Linton. 'Now there is a feeling of even more luxury. In an ideal world, bathrooms would be double the size, if you could afford the square metre-age to do it. There has been a revolution in the materials we can use - they have become much more luxurious but still suitable for the job. Previously it was difficult to find luxuriously tactile fabrics that were hard-wearing enough to use in a hotel. There are many more materials on the market now, such as exotic veneers for furniture, shaped glass and metals.'

In One Aldwych's sister hotel in the Caribbean, Fox-Linton used perspex shelving and fibre-optic lighting in the library. 'This makes the room look cool during the day and then at night it lights up with blue-glowing boxes or pink-glowing boxes or green-glowing boxes among all the planting. It's rather fun,' she says.

The biggest challenge to any hotel designer is how to marry two contradictory elements. How do you create a space that feels like home from home while at the same time giving the impression of stepping into a different world?

The major chains, whether they cater for the top end, the business or the budget traveller, all have a brand identity. Marriott, Ramada Jarvis, Swallow, Travelodge or Thistle all have a distinctive look, so it feels familiar to regular customers where ever they are in the world. Holiday Inn even used to make a point of positioning its light switches in the same place in every hotel around the world, so that however jet-lagged you were, you could always find it straightaway.

'In addition to a distinct brand look and feel, each hotel's design takes into consideration functionality for our guests, locality, cost, availability of products, energy efficiency and environmental responsibility,' says Patrick Fitzgibbon, senior vice president, development, Europe and Africa at Hilton International. 'New property and renovation designs are in keeping with 'the new face of Hilton'.

Few of the upmarket hotel chains can afford to ignore the threat of the boutiques, and most have their own ultra-modern offerings. Two years ago, InterContinental, the world's largest hotel group, unveiled a new hotel brand with a spacious contemporary decor called Hotel Indigo, aimed at 'style-conscious' mid-range travellers. The fourth of these properties opened this summer in Houston, in the US. The company describes Hotel Indigo as 'a branded boutique experience', which, it says, offers 'stylish accommodation and a personalised service experience in a unique and intimate atmosphere'.

Hilton has a number of high-end properties around the globe with what Fitzgibbon calls their own unique style. These include the new Hilton Canary Wharf, Hilton Sydney, Hilton Kuala Lumpur, Hilton Maldives Resort and Spa and the soon to open Hilton Tower Bridge. 'The innovation extends to other Hilton products and services,' he adds. 'These include new cutting-edge relaxation rooms, spas, business and leisure amenities, restaurants (such as the new Galvin at Windows at the Hilton on Park Lane and the new undersea restaurant at the Hilton Maldives Resort), bars (including the funky Zeta Bars in Kuala Lumpur, London and Sydney) and guest services (from self-service check-in to butler services). Hilton's hotel and product designs are selected to give our customers the best possible guest experience.'

But there will always be a place for the traditional hotels, whether they be quintessentially English, Parisian or Roman. 'You wouldn't want to pull the guts out of the Ritz-Carlton, would you?' says Fox-Linton.

'Traditional hotels, the grande dames of Europe, if you like, may upgrade subtly but they will not undergo a radical change. Nor should they. It's rather like the design of a bottle of Gordon's gin. It has had 100 different changes over the years to bring it up to date but no one ever notices.'

The five-star May Fair Hotel, part of the Radisson chain, has recently undergone a £75m refurbishment programme and a return to its former glory.

So while it still provides the elegance and opulence of a bygone age, it also caters to the demands of its 21st century clientele.

Ultimately, change comes because customers want it. More and more people are demanding better interiors when they go into a hotel, because they expect it in other aspects of their lives. Customers are much more aware of interior design than they used to be. They may not remember what it looked like, but they will remember how it made them feel.

'The public want cleanliness - and why shouldn't they? And they want comfort. Why should they be expected to eat a four-course meal sitting on an uncomfortable chair?' asks Mary Fox-Linton.

TOP 10 HOTEL OPERATING COMPANIES IN THE UK, 2003 AND 2006

* Marriott data included with Whitbread Group in 2003

Source: Mintel; company data.