Taking flight.

Roissy, one of Europe's most functionally exasperating airports, keeps on getting larger, but this new addition actually attempts to celebrate air travel through a series of elegant, luminous volumes housed in an inventively engineered structure.

Roissy Charles-de-Gaulle is one of the most exasperating airports to use in the world. Roissy I (the terminal in the shape of a drum with escalators in transparent tubes slashing diagonally across its dreary central space) so lacks any notion of directionality because of its circular plan that disorientated travellers wander round muttering to themselves in rage and bewilderment. Roissy 2 overcame lack of orientation by being strung out as a series of disjointed crescent-shaped halls to north and south of an axial road transport spine. But anyone who has tried to sprint from one hall to another to catch a connection, or (in some ways even worse) has had to trundle around in nail-biting slowness on one of the Heath-Robinsonish buses where the floor ponderously moves up and down on gigantic scissor jacks, knows that this is not much better, The chief architect of both buildings was Paul Andreu.

Now, he's had another go and it looks as if he's learned a good deal from previous experience. Hall F of Terminal 2 is roughly the same shape as the previous halls, but is much bigger than they are. Two peninsules, each with a dozen air bridges, project from its curve. Departing passengers enter at the upper level from the road spine (which connects the nearly completed complex to the rest of the airport via the TGV and RER station - AR February 1995). Arrivals are at the lower level and debouch into a triple-height canyon over which bridges connect the road spine to the check-in hall, which follows the curve of the crescent. The idea of the gulch is reminiscent of the huge canyon at Kansai where Andreu and his team were instrumental in organizing flows of people and luggage (AR November 1994).

From the check-in hall, departing passengers have to move out through security checks into one of the two peninsules, which are elegant spaces tapering progressively forward in plan and section. Curved glass walls and a sort of space-frame roof make them into luminous and calm spaces. The check-in hall is handled in a quite different way, with the whole space enclosed by a shallow smooth grey concrete vault which has an amazing 74m unsupported span. For comparison, the Pantheon's diameter is less than 45m, and while no one will ever claim that Roissy 2F aspires to the nobility and intensity of the great Roman building, it is a considerable step forward for the Andreu team, which up to now has tended to produce rather dumb spaces, both in Paris and elsewhere like Djakarta (AR November 1995).

The great span is achieved in a curious way: by hanging a thin concrete membrane from a steel structure of huge curved girders stiffened by longitudinal steel members. The whole is clad in zinc, which is regularly cut back in huge ovals to reveal the concrete inner parts pierced by little square windows. At the ends of the curved hall, the concrete emerges as a sort of pierced tube, as if the building is spilling its guts. But one must not be too critical - Andreu and his people have created at least one memorable space, and a building that is far more simple and easy to use than their previous efforts.

And in doing so, they have been incredibly brave with construction. Most of us would be very puzzled about how to create what must (at least to some extent) be a stiff, rather brittle concrete shell within a flexible steel structure. But they have invented the new system and executed it with true Gallic panache. Only sceptical Anglo-Saxons will be looking for cracks as they rush through the fine space to catch the next plane to Djakarta.