Clear cut.

This late twentieth-century successor to the Modernist ideal of a glass house reinterprets the canon in the current Post-Modern age as a multi-layered, ambiguous place.

On a secret part of the coast of Japan there is a place where, millions of years ago, ancient lava flowed into the sea and formed a series of high thin promontories stretching east into the water like the outspread fingers of a gigantic hand laid flat on the floor of the world. Now the fingers are covered with a natural forest and the back of the hand has been terraced before it starts to slope sharply up towards the mountain.

Poised on the edge of the lowest terrace, just above the cliffs round one of the inlets between the fingers is a long, low thin house of steel and glass designed by Norman Foster. It hovers over a timber deck cantilevered from a raised concrete slab, and floating over the whole is a thin and elegant flat roof. This is supported on pairs of white painted tubular steel columns, each 9 m apart, and 4.5 m away from the next pair. Each pair carries an 1 beam which projects tapering in cantilever to the edge of the roof on each side; the frame is completed by joining the columns longitudinally with 1 beams.

In each bay between the columns is a pair of sliding full-height double glazed doors in aluminium frames, so the interior can open on to the desks according to the state of the weather and the mood of the inhabitants. From the entrance, on the west (uphill) side, the house is completely transparent, and the marvellous view of the wild promontories and the sea is immediately revealed. To the right is the living room, which also enjoys the view, but is protected from visitors' observation by two storage areas clad in solid aluminium panels with a white baked acrylic finish. They project between the columns under the cantilevered canopies and over the decks. Foster calls these "plug-in service modules" and has enclosed all ancillary areas (plant, kitchen, and bathrooms) in such enclosed boxes which alternate between east and west to offer different landscape views.

But all the main living spaces can be joined on the long axis by sliding back screens to throw them into a long enfilade volume. The thrust of the internal axis against the superb cross views of the landscape is greatly emphasised by the insulated louvres of the ceiling, which can be moved according to the position of the sun and clouds to throw natural light along the whole volume. (The elements can be further modified by external blinds that can be rolled out electrically over the gentle shallow pitches of the glass roof.)

This long and noble space is made complex by the varied interaction of the cross and longitudinal axes, by the simple elegance of the finishes (all metal is white, partitions are lined with pale grey silk and the floor is covered with natural sisal carpet bonded to the concrete floor slab). There is a continuously changing balance between human based space and primeval nature, between the superb artefacts and the wild shapes of the trees and rocks.

Over the bedroom, the glass sheets of the roof are replaced by similar sized panels of solid aluminium with the same finish as the walls of the plug-in modules. Here there is a flat impervious ceiling of pressed aluminium panels and the glass walls are made translucent by diaphanous blinds. To the north of the main house there is a little guest pavilion which uses the same disciplines as the main building, though the roof is entirely like that of the master bedroom. This is a delightful little place in itself, though without the clarity of the larger building, which it lacks partly because its deck extends to spread round a fine existing wild cherry tree and a rectangular swimming pool served by a spring which brings hot water from the bowels of the mountain. (As many trees as possible have been kept on the site, and they are enhanced by new native planting.)

The house is plainly a successor to the Farnsworth by Mies and Philip Johnson's at New Caanan. These were celebrations of Modern dematerialisation of enclosure, and both highly Classical in conception, with services internalised to allow the facades to be regular. Foster has placed the services outside to allow a more ordinary way of life to be pursued. The Farnsworth and Johnson houses are essentially holiday places which formalised the notion of a clearing in the woods with sleeping, eating and cooking places scattered about almost at random on the artificial raised ground of the floor plane. In a sense, this example is a glass house seen through the eyes of Post-Modernity (p4).

By moving the services to the exterior, Foster has been able to create a house that can be used all year round, one that offers both pleasures of containment and revelation. In making a controllable glass roof, he has been able to generate a further dimension of interpenetration of interior and exterior -- the heavens become part of the contained experience.

By permitting the plan to expand and contract within the thin ordering planes of roof and deck, he reinvokes some of the accretive quality of traditional Japanese planning, while inside he creates a very Western enfilade modified by sliding Japanese screens. The place is a blend of outstanding subtlety that combines ancient and modern, artefact and nature, interior and exterior, Europe and Japan.