Japanese lantern.

With well-dressed bodies sleeping rough on the street outside, two days before its doors opened to the public, Hermes' new Tokyo flagship store can clearly disregard Japan's current economic recession, the most serious since the war.

This building's inspiration was as much cultural as commercial, an expression of the principles that have underlain Hermes products for generations - handmade craftsmanship and quality materials -- and the way that these characteristics are consistent with the historic architecture of Japan.

It is within this context that Renzo Piano established his design. With a museum, gallery and cinema, this is effectively a themed public building rather than purely a commercial space.

By day, the curved planes of the glass-block veil flicker and glisten and transform the chaotic streets outside into subtle shades when viewed from within. By night, the building becomes what Piano describes as 'a magic lantern' - a vast glowing crystal that establishes, by the light it radiates, a territory around itself -- a new public space in a city that conceives of such things as places of event, rather than urban geometry. Suspended from the top, the glass veil expresses mass but at the same time defies gravity- its support system being imperceptible. And, on this long, narrow site -- only 12m wide -- the translucent wall creates interior spaces that are both intimate and infinite.

This was not easily done. The glass blocks are the largest ever made -- 450mm square -- cast in Italy, then hung in Tokyo in a steel frame transported from Switzerland. It is a marriage of handcraft and high-precision engineering, each block being unique -- the glass poured by hand into single-sided moulds, leaving different flow-lines and imperfections -- a differentiation that is crucial to Piano's vision that this project be clearly the work of artisans.

The large size of the blocks was determined by Piano's wish that this be perceived as a translucent wall, not as a net of opaque horizontal and vertical joints. For the same reason, he rejected assembling the blocks within a steel-frame super grid that prevents lower blocks being crushed by those above. Instead, each block is supported individually between slender steel bars that are silvered on each side face, rendering them all but invisible, and which allow 4mm movement at every joint, in both directions, to cope with seismic disturbances.

Integral to this concept is the revolutionary flexible design of the building's long, thin structural steel frame. At 50m tall and with a main structural span of only 3.8m, the unusual slenderness of the structure results in high overturning moments during an earthquake and high levels of tension in the columns. The engineer, Ove Arup & Partners, found inspiration in the tall, thin wooden Buddhist pagodas of Japan. Records show that, in the past 1,400 years, only two have collapsed -- believed to be because the columns are discontinuous from floor to floor. In the Hermes building, the same principle was adopted, with the columns on one side of the frame being held in base joints that allow uplift and rotation simultaneously and seismic energy to be absorbed by viscoelastic dampers. This is the first building of modern times to have columns that lift off the ground in an earthquake.

One particularly fascinating aspect of the interior spaces is the way that, despite the different palette of Piano and Rena Dumas -- the interior designer of Hermes' shops worldwide, including the lower five floors of the Ginza building -- there is convincing consistency between all parts, which Piano describes as the consistent 'vibration of work done by hand'.

Dumas' spaces are elegant, discretely lit arrangements of fine wooden furniture and precious tactile materials, generously spaced to reveal the glass-block perimeter wall at all times. Piano's upper levels are handcrafted in an entirely different tradition, with precisely detailed partition systems, minimalistic steel-frame doors, exposed light fittings and electric raceways -- all rigorously controlled, and meticulously fabricated and assembled. These different, but complementary, approaches to spacemaking are united, appropriately, by the products they display, the works of the painstaking Hermes craftsmen.