'The target market has remained consistent over the years but it has been affected by this increasing mobility.

'This is tied to the way companies are working. With so many mergers and acquisitions [going on] more companies have become multinationals and they move people around more often than before. It is not such a big thing for a company to move someone to Hong Kong as it was five or 10 years ago,' Mr Jensen says.

'We also see more individuals who want a hassle-free lifestyle where everything is taken care of and provided, including home furnishings and maid service,' Mr Jensen says.

'So there is an increase in demand because there is an increase in mobility and that is what has caused this to happen.'

More people are also looking at serviced apartments as an alternative to hotels.

For about the same price as a five-star hotel room they can have most of the facilities and benefits - and more space, more privacy and the ability to have meals at home.

'There are certainly more people using serviced apartments as an alternative to hotels for longer stays.

'The benefits are obvious as they get more space and facilities for basically the same price and they have the ability to make drinks or cook meals. And they still have more privacy than at a hotel as there are fewer people entering the apartment building than at a hotel. The only real difference from a hotel is that we don't provide room service, but we do have restaurants, a coffee shop and a supermarket [nearby].'

While many families used to move into hotels when their flats were being renovated, a growing trend is to move into a serviced flat instead.

'More Hong Kong families are renovating their own apartments so they might move in for a period while they are carrying out their own renovations,' Mr Jensen says.

'There is a very limited supply of new apartments coming on to the market at the top tier, and hardly anything to speak of on the south side of the island.'

Serviced apartments are in three broad categories. While monthly rents vary between districts, standard flats generally run from HK$20,000 to HK$35,000 per month. The mid-range runs from HK$35,000 to HK$50,000 per month, while the premium or luxury sector starts at HK$55,000 per month - and the sky's the limit.

'Over the past four or five years the market has been broadening. There are a lot more tiers than there were before,' Mr Jensen says.

Gary Cheung Lai-wan is business development and operations manager at Wincome Management Consultants, which manages Central 88 (at 88 De Voeux Road, Central) and Happy Valley 88 (at 42 Blue Pool Road, Happy Valley) luxury serviced apartments.

She says that serviced apartments are increasingly seen as a cost-effective alternative to hotels.

'Expatriates require quality, spacious, luxurious homes with five-star concierge services, but reasonable and affordable prices,' Ms Cheung says, adding that serviced apartments can provide 'a better value alternative to hotel accommodation'.

Catering primarily for expats relocating to Hong Kong, the two properties tend to attract executives working for multinationals and in the fields of banking, finance, information technology and law.

One change in the marketplace in the past couple of years is the growing acceptance of serviced apartments by Asians. Just three years ago, Americans accounted for 55 per cent of residents at the two properties, followed by Australians (30 per cent), but there were few Asians.

Now, the American ratio has dropped to just 30 per cent, with Asians - including mainlanders, Koreans, Indians, Singaporeans, Japanese and Taiwanese - accounting for 50 per cent.

Some serviced apartments are making changes to cater to the requirements of this evolving clientele.

'To meet market needs, we have added ... a Putonghua speaker to our concierge service, Asian items to our breakfast menu, TV channels with mainland programmes and magazines in Chinese,' Ms Cheung says.

According to a spokesman for Gateway Apartments in Tsim Sha Tsui, location and convenience are the top points people take into consideration when choosing a serviced apartment.

'The apartment should be conveniently located to minimise travel to and from the workplace, and have easy access to public transport,' he says.

'When residents are staying for conferences/trade fairs, proximity to the venues is important. For families, consideration of the accessibility to schools also plays an important part. Harbour views are the priority for some residents, especially those who can afford to pay a premium.'

Other important considerations include cost, brand recognition, the quality of services, the layout, design and spaciousness of the flat, security, furniture, fixtures and fittings.

But for expats who may be living away from their country for the first time, there are other considerations.

'Residents are drawn to similar and like-minded neighbours, [so there tends to be a] cluster of nationalities, colleagues and associates,' the spokesman says.

'Gateway Apartments has a substantial number of Japanese residents and pilots.'

Clubhouses are another important factor and they need to offer a full range of sports, recreational and spa facilities, and dining and social activities.

'The number of TV channels, cable TV, high-speed internet connection, proximity to shopping, dining, entertainment, nightlife and cultural events [are all important],' the spokesman says.