Sony central.

Sony and Daimler Benz are at loggerheads. Their sites are separated by Neue Potsdamer Strasse, soon to be one of the busiest roads in central Berlin. They seem to be competing commercially as well as in architecture. Is this the way to make a city?

The Sony site is immediately north of the debis area, but is much smaller. The perspectives and models of the two schemes are instructive, for neither side shows the work of the other developer and his architects, except occasionally and very sketchily: if there was any collaboration at all, it clearly has not been close. Indeed, the two projects are in competition, with Sony having started two years after debis (p36). Of course, Sony had to follow the perimeter road pattern, but their architect, Helmut Jahn of Murphy/Jahn was critical of the Hilmer and Sattler masterplan (which still to some extent lies under the Piano scheme), and with some justice Jahn pointed out that the masterplan's form of critical reconstruction (p30) in which the traditional block structure is reproduced 'is not spatial. The blocks introduce a static order and rigidity'. So he largely ignored the proposals of the masterplan, and tried to generate a scheme which will 'combine a formal, spatial and technical Vision and Order'.

At the same time, Murphy/Jahn were concerned to produce a piece of 'modern, technical city representing the Commercial Strength and Technical Capability of one of the world's most powerful and successful corporations. These can be the force behind a workable Reconstruction of the City'. Even the mighty Daimler Benz was not as brash and triumphalist as this and, for all his extraordinary achievements, Piano's approach is almost the antithesis of such an attitude.

Yet Jahn has a point. These great corporations have invested huge sums into the regeneration of Potsdamer Platz, they have a right to be recognized. Their predecessors in the '20s and '30s never had a doubt about covering buildings with flashy signs - they were one of the attractions of the place, helping to make it glitzy, exciting like Piccadilly Circus or Times square. At one level, Jahn wanted to make his whole complex into a huge advertisement for Sony and its entertainment products, and he has certainly succeeeded.

At the apex of the site, against the Platz itself, Jahn has built a tower to form a group with those of Piano and Kollhoff. Never can there have been such a strangely assorted trio: Kollhoff's clumpen grim brick Rationalism is set between Piano's delicate terracotta filigree and Jahn's smoothly flash curved glass tower. It is not badly done (still as yet only half covered, but it is clearly going to be a sophisticated piece of cladding technology). But, unlike the other two, which in contrasting ways speak of rootedness in Berlin, Jahn's tower could be anywhere from Singapore to Seattle.

To try to give the Sony site a sense of particular place, Jahn has created a huge semi-public space (the forum) immediately behind the tower. It is topped by a most ingenious tensile roof which is to be made like a vast truncated wigwam: an unforgettable sky-line that, with its frilly alternating gores of glass and fabric, will glow at night, beckoning to the whole area. Opening off the forum will be shops, cafes and entertainment complexes of various kinds including an IMAX (does the area really need two?). At the west end of the site, where it looks over the Kulturforum and the Tiergarten, will be more or less conventional offices, partly occupied by the Sony European headquarters. The spatial moves between these could be interesting, though the streets and small public spaces will be a bit canyon-like (not perhaps inappropriate for the place which wants to become the focus of Berlin-New York again).

Clearly, the forum is the demonstration of Jahn's will to make modern urban space, but as yet (the roof is not on) it is impossible to judge what its quality will be like. It will certainly be very big - at the perimeter, 11 stories high, and much taller at the apex. On lower floors of the Neue Potsdamer Strasse side (south), there will be the Filmhaus and mediatheque. On the north side, remains of the Esplanade will be assembled behind glass under a suspended structure held up by a gigantic triangulated truss. (The Esplanade was one of the best hotels in Berlin before the War; it was bizarrely preserved in the death zone east of the Wall). Its fine rooms will be recreated in various ways; its bedrooms are to form some of the most expensive flats in Berlin.

The forum walls are penetrated by big holes and chasms which connect it to the surrounding streets. The architects claim that the geometry will reduce wind velocities in the forum to a tenth or a quarter of those outside. Doubtless, the prediction has been most carefully checked, but it will be interesting to see whether such projections about what appears at first sight to be a gust engine will prove to be correct. Other environmental predictions are more obvious: clearly the wigwam will modify the temperature of the forum, keep it largely free of rain and snow, and to some extent modify the interior climates of the surrounding rooms by reducing heat gain and loss. But in general, spaces are conventionally air conditioned - there is no attempt to achieve environmental innovation, as there is on the debis side.

Conventional interiors are matched by conventional international exteriors in steel and glass. The big gestures: wigwam, forum, huge aggressively Berlin truss and so on, may rescue the place from banality. It may become a loved landmark and a popular place to go to. But it seems much more likely that Heinrich Weifing's prediction (p30) of public space being appropriated by the powerful private corporation will come true on the Sony site rather than on the debis side. P.D.