Eagle-eyed C20 members visiting the capital will have rejoiced in the mysterious disappearance of the infamous ‘Swiss light’ –the illuminated box at the top of Tate Modern’s chimney. C20 had always opposed this element of the otherwise excellent conversion scheme and we were glad that it had been removed. For a while Sir Giles Gilbert Scott’s masterpiece is restored to its elegant and imposing, domination of the south bank. However, a large extension to the Tate is now set to go ahead, and even be rushed to completion in time for the 2012 Olympics. The Tate already has planning permission for an eleven-storey ‘Tate 2’, designed as a series of staggered boxes, by Herzog and de Meuron. A new, more architecturally refined, version of the scheme now seeks approval. Rendered in a ‘perforated brick’, the proposed structure pertains to harmonise with Scott’s sober brick surfaces, appearing to punctuate a (rebuilt) southwest corner and rising, like a growth, out of the station to confront the Thames. One exciting consequence is the utilisation of three subterranean oil tanks, vast shuttered concrete caverns that will provide exciting installation spaces and enhance the visitor’s understanding of the building’s former use.
The Tate argues that the new block will hold its own amidst the new towers and high rises expected to creep up along both the north and south banks of the river. Yet Scott’s elegant symmetrical arrangement, dense form and slender tower already makes a clear silhouette and an iconic statement. The surrounding space is powerful for its emptiness, creating a ‘breathing space’ in the dense urban grain and a special relationship with St Paul’s cathedral. By the day the brick façade will read as a heavy and solid mass; by evening, lit up inside, the extension will glow and buzz with activity, detracting and competing with the black silence of the chimney. An extension of such height and mass will even threaten the existing (and popular) alterations by the Swiss firm, whilst the cathedral-like character of the great turbine hall will become busier and louder when newly-punctuated by the extension and further openings.
It is not without irony that it was the unlisted, and therefore adaptable, status of Bankside which encouraged its acquisition by the Tate in 1993. As is stands, the gallery could be a rare and exemplary story in preservation. Conversion has ensured the re-use, reappraisal and celebration of a significant C20 masterpiece allowing Scott’s work to survive and preside over the rapidly-changing riverside with dignity. Yet Tate Modern has become a victim of its own success and today suffers from overcrowding. Tate also wants to provide more display and education space. We fear that the resulting extension will overpower its originator and intrude on the building’s unique relationship with the south bank and the City. The Tate Modern does not need new architecture to make its presence known to London. It already has a monument that is stunning in its simplicity and restraint; one whose fine brickwork will stand out more and more clearly against an ever-growing backdrop of glass and steel towers. If it does want to commission a stunning piece of C21st architecture, perhaps it needs a third London site to put it on?