So it is real, red-blooded architecture, and amazingly it is neither shiny nor hard-edged. This is brave, because the familiar photogenic glossy look - particularly when shot at twilight, the shiny architect's favourite time of day - helps a building's media image no end. Matt-finish, blurred-edge buildings such as the Downland Gridshell are less camera-friendly and suffer as a consequence. But the upside of this is the revelation when you visit in person, just as the downside of many reflective industrial-chic buildings is disappointment in actuality. The Downland Gridshell, tucked into a wooded hillside as it is, is commendably self-effacing. A standard industrial shed, containing the same floorspace, would stick out like, well, like a standard industrial shed. And at around £1.5m, the Gridshell even manages to be good value for money.

Its building technique was as audacious as its finished state. Most buildings, understandably enough, start on the ground and are then built upwards. This one started in the sky and then reached downwards. Strange but true. Slender lengths of oak were joined until they formed lengths 120 feet long. Then they were arranged in a computer-calculated double-layer flat rectangular lattice, perched high in the air on scaffolding. Then the edges of the grid were lowered, very gradually, until the building formed its predicted undulating, self-supporting shape. Finally the edges were fastened into place and the cladding applied. Although the principle of the gridshell has been known for years, and examples have been built by the German engineer Frei Otto, none had been built this way before. It takes the idea to another level, rather as Sir Nicholas Grimshaw's Eden Project advances the cause of Buckminster Fuller's geodesic dome. Both, curiously enough, are in rural settings.

This is important. The countryside is the next frontier for imaginative architects. In Britain - and particularly in southern England - there is no getting away from the fact that huge amounts of rural building will be necessary, soon. Among all the houses, there will be the need for bigger buildings. Nobody wants big intrusive new objects in the countryside, although everybody there uses them. Everyone pays lip-service to the idea of sustainability, but nobody thinks how to reconcile this with a rural building boom. Well, everyone: here's a rather clever answer. A big building that grows itself, defies gravity and vanishes into the landscape. And which still manages to be architecture of a high order. It's an idea well worth pursuing.