JAPANESE MINIATURE.

With extraordinary invention and ingenuity, Kazuyo Sejima fits this tiny house into the densely woven, indifferent texture of downtown Tokyo. Curiously, for all its apparent wilfulness, it draws its origins from its very tight site.

Today more than ever the small house serves as a testing ground for architectural ideas. In few places is the ground so testing, so expensive, crowded, and prone to tremors, as central Tokyo.

And in few societies are ideas and, it might be added, trends so tenaciously pursued as in contemporary Japan. Kazuyo Sejima's Small House is easily found at the end of a short cul-desac in Tokyo's affluent Aoyama district. It's a miniature tower containing 77 square metres of floor area on an allowable imprint of 36 (the site measures 60 square metres in its entirety).

The house is wrapped in opalescent glass and galvanized steel with a vein-like standing seam. From the lane, there are only glimpses of life through the house's western translucent zone and occasional small transparent panels. Furthermore, the clients claim they did not want expansive views out, as the house overlooks the Sony establishment where the husband works as a product designer. A vertical pavilion almost touching its easterly neighbour, the house bulges in the middle, then tapers in towards the roof (a space-age mansard?) and down towards the entrance. There the slope inward accommodates - to the centimetre - the family's silvergrey Honda van.

To south and east, the skin is mostly opaque and hides several service hatches. It is made almost entirely of glass; however, to the back and to the west, a landlocked lot belonging to an adjacent temple provides Sejima's clients with views of greenery and, metaphorically at least, some breathing space. The building is structured about an open steel shaft with inner spiral stairs; both are painted white. Each floor spreads from this trunk to rest on thin steel tubes slanted at varying angles about the perimeter. The outer skin is simply laid against this cage. Ground level entry steps are formed from a folded plane of concrete; external metal rungs provide service access to the roof above.

The architect has divided the programme into four distinct elements. In a semi-basement is the parents' room with storage recessed beneath the clerestorey fenestration and a tiny lavatory. Raised slightly above street level is the hall and guest bedroom. On the piano nobile -- the broadest and tallest space -- are kitchen, dining and living quarters (one shelf has an eye-catching display of recent Sony products). The house terminates in a bipartite zone with a comparatively grand bathroom and an enclosed roof terrace that looks across the empty lot to the towers of Shinjuku in the middle distance.

The chamfered form of the Small House results partially from neighbourhood zoning and sunlight demands: it's a miniature cousin to Hugh Ferriss's 1920s images of metropolitan massing. The canted sides are however determined more by Sejima's strategy of stacking, a strategy shared by such current vanguard projects as MVRDV's Dutch Pavilion at the Hanover EXPO (AR September 2000). In Sejima's work, the envelope becomes fabric stretching between differently-sized slabs. The floors themselves are concrete, held between an ingeniously engineered steel cage.

In a climate prone to chilly winters and warm, rainy summers, the Small House has only a few operable windows, mostly to the east. It is expected to act as an inhabited flue, warm air rising to be expelled upstairs. Floor-to-ceiling expanses of glass are screened by thin slips of white curtain. Sejima's independent work, and that in association with Ryue Nishizawa, is marked by ostensibly contradictory characteristics: it appears both functionalist and natural, machine-like yet so delicate as to be almost ephemeral. With the large glass panels tilting in both horizontal and vertical directions, the Small House seems less like a tree house and more like a tree itself, a weeping willow perhaps.

1

A space-age mansard?

2

Form of house is generated by rights of light regulations.

3

House becomes transparent at the back, overlooking temple grounds.

4

Constant interplay between translucency and transparency.

5

Open steel shaft core.