OPTICAL ILLUSIONS.

Built to house a small collection of the work of Hiroshige Ando, one of Japan's greatest woodblock artists, this museum echoes the artist's sense of delicacy and dematerialization through an architecture of enviable simplicity and precision.

Kengo Kuma's recent work explores different routes towards a singular goal: the dematerialization of buildings of diverse type and scale. In the Glass/Water house in Atami (AR March 2000), an oval dining pavilion of glass appears to float on an infinity pool that extends visually from a cliff to the sea far below. Precast concrete wedges attached in an irregular pattern to a steel grid wrap around a recently completed parking structure at Takasaki, animating the multi-level block, reducing its bulk and creating a strong urban identity in the chaos of the station forecourt. Cedar louvres clad a Noh theatre in Miyagi and protect the inner shoji screens of a guest house on the Miura Peninsula near Yokohama.

The Hiroshige Ando Museum employs a similar strategy, though it appears at first sight to be nothing more than an utterly simple rectilinear, steel-framed shed of cedar slats, with a public right of way cutting through one end to divide the shop and cafe on the left from the galleries to the right. It was endowed by a collector of Hiroshige woodblock prints (ukiyo-e) who left home to make his fortune and wanted to be remembered in his birthplace, the small provincial town of Bato, an hour's drive north of Tokyo. For Kuma, the challenge was to protect these light-sensitive treasures, and to create a sense of place in a banal townscape.

The shallow-pitched roof flows seamlessly out of the walls, creating a symbolic shelter that seems to dissolve as you draw near - much like the sharply cut lines that Hiroshige used to represent a downpour. As Kuma explains: 'The idea was to subdivide the architecture as much as possible and treat it as a cloud of particles floating in the natural landscape ... transience and fragility is their charm, their very essence'. In doing this he found an ideal metaphor for the prints, which celebrate sudden showers and the short-lived blossoms of spring as well as the sensual 'floating world', of the Edo pleasure quarters.

A love of the ephemeral and the illusory is quintessentially Japanese, but Kuma's architecture is tough, not pretty. The neat precision of the slats and their meticulous detailing is closer to the work of Peter Zumthor than to traditional Japanese wood buildings in which natural irregularities are prized. Here, the wood is as sharp-edged as steel sections. The glass skin of the lobby and the concourse to the north reveals and reflects the slats within, intensifying the interference patterns and the illusion of multiple layers that you sense on approaching the museum. Aluminium rods suspended within the glass are echoed in the tall backs of wheeled benches that line the concourse, adding another layer of linearity and texture.

Backlit panels of washi (hand-made paper) form the inner skin of these circulation areas and the same material is used to wrap wooden pots, creating an appropriate transition to the works on paper that are displayed in softly-lit galleries at the core of the building. The monochromatic palette of cedar, dark Ashino stone, cool aluminium, and soft-textured cream paper instil a feeling of serenity, providing a decompression chamber between the prosaic grind of contemporary Japan and a window on the world of Edo. And, as Kuma insists, appreciation of materials and their vibrancy is heightened when they are divided into discrete particles of carefully calculated size and spacing. Within the galleries, slatted drop ceilings create an appropriately intimate scale, and dark blue walls complement colours that have survived undimmed in these extraordinary examples of Hiroshige's artistry.

WOODBLOCK PRINT MUSEUM

BATO, JAPAN

ARCHITECT

KENGO KUMA

1 Sharply incised lines of Hiroshige's prints echo the dematerialized form of the building. Shown here is A Sudden Shower over Ohashi and Atake, 1857.

2 Shallow pitched roof flows seamlessly out of the walls, so that the barn-like volume of the museum appears to float lightly in the landscape.

3 Sharp-edged cedar slats recall the meticulously detailed yet highly sensual work of European architects such as Peter Zumthor rather than vernacular Japanese timber buildings.

BATO, JAPAN

WOODBLOCK PRINT MUSEUM

ARCHITECT

KENGO KUMA

6 Circulation areas are enclosed In an inner wall made of wash (hand-made paper). The wail is backlit to create a zone of decompression and transition between exterior and galleries at the heart of the museum.

7 To preserve their delicate contents, exhibition spaces are calm, softly-lit chambers, sealed off from natural light.

Architect Kengo Kuma, Tokyo