British Airways and the British Airports Authority (BAA) declare that it will redefine the airport experience. Those arriving from Hong Kong next Thursday will be desperately hoping this is true.

The tatty, outdated, sprawling and overcrowded Heathrow of recent years is enough to reduce even the most refreshed longhaul flyer to tears. The existing Terminal 2 was opened in 1955 by Queen Elizabeth and is still used today. This explains a lot.

The aim is to make the 30 million BA travellers passing through T5 every year forget that they are in an airport at all. On their journey through the terminal, passengers will be surrounded by glass, steel, marble, polished wood, works of art, Bond Street style stores, upmarket eateries and stunning views of the surrounding landscape. Let's hope they don't forget to get on their flights.

Nearly 20 years in design and built by 20,000 workers, the 4.3 billion pound building has been described as 'one of the most breathtaking man-made spaces in modern Britain' by the Guardian's architecture critic, Jonathan Glancey. And it certainly looks very impressive in shots of the vast empty halls with no pesky passengers and their baggage messing it all up.

Architect Mike Davies and firm Rogers Stirk Harbour and Partners are responsible for this creation, as well as the Welsh Assembly building and the Pompidou Centre in Paris.

The new terminal is located on the site of a former sewage works and is currently the largest freestanding building in the UK at a mighty 40 metres high, 396 metres long and 176 metres wide. There are five levels, each one the size of 10 football pitches.

By 2011 there will be three buildings linked by an automated passenger transit system. The departure hall contains 96 check-in kiosks for self check-in; there are 20 security lanes and the biggest, single-terminal baggage handling system in Europe, containing 18km of belts and the capability to transport 12,000 bags an hour around the terminal.

All this has been designed with speed, efficiency, light and space in mind. The vision is of calm, relaxed travellers passing serenely through the airport with no nauseating stench of burgers and fries.

This week Robert Boyle, Commercial Director of British Airways, said: 'The opening of Terminal 5 heralds a new era in air travel. Customers can look forward to a calmer, smoother, simpler airport experience at Heathrow...'

The array of luxury brands and top-end high street names is an airport first, with Tiffany's, Harrod's and Prada among those lining up to start trading next week. Michelin-starred chef Gordon Ramsey is opening his first airport restaurant, Plane Food, and the fast food chains are conspicuous by their absence. Instead, its caffeine overload with all the usual coffee shops and cool high street favourites including Carluccio's and Wagamama.

Paul Smith is opening a new store called 'Globe' at the terminal and says, 'We are always looking for unique opportunities to create something different for our customers, and the landmark nature of Terminal 5 fits that need absolutely. From the design of the building itself through to the focus on delivering the best for the traveller at every stage of his or her journey, we like what we see.'

BA has invested in six 'boutique hotel' style airport lounges and there is also an Elemis Travel Spa. This summer the luxury Sofitel will open, one of many Heathrow airport hotels but the only one to adjoin Terminal 5.

Trying to reduce the pain of air travel for families, the terminal incorporates three children's play areas and full baby changing facilities in all toilet blocks, some with feeding chairs.

Comfortable leather seating and easy-to-see 'beacons' - displaying flight information - complete the picture of airport perfection. The transformation of the rest of Heathrow is planned to coincide with the 2012 Olympics in London.

T5 has already been outshone by new terminals at Beiing and Madrid Barajas airports in the press. Concerns have been raised about the enhanced security measures for domestic passengers at the new terminal and their effect on queues and waiting times. There has also been criticism of the use of buses to transfer passengers from the terminal building to planes on a significant number of flights.

After all the designing, planning, building and extensive trials using thousands of volunteers, I hope that Heathrow Terminal 5 is a success and the refreshing experience envisioned by those who created it.