On 1 November 2012 it will be twenty years since the Rotterdam Kunsthal first opened its doors to the public. Not long afterwards the Netherlands Architecture Institute (NAi) by Jo Coenen was completed, along with the connective green space of Museum Park, on which OMA had collaborated with Yves Brunier and Petra Blaisse. The NAi–Kunsthal axis, and at right angles to it Witte de Withstraat, which was revitalized in the same period, with cultural centres like the Witte de With museum and the later extended Museum Boijmans Van Beuningen as hinge point, are the consummation and highlight of the municipal policy of reinvigorating the city centre with an injection of culture and architecture.

    In the intervening years the NAi has undergone a couple of refurbishments and successive directors have continued to wrestle to fit activities into the various rooms, interspaces and outdoor spaces. Museum Park has only recently reopened after the long drawn-out construction of an underground car park, nicknamed the Blunderput (blunder pit). In all that time the Kunsthal has remained unchanged and successive directors have managed to make it an unexpected success, despite the lack of a collection and a programme. That probably says something about the quality of the those directors, but it also says something about the building: it is extremely accommodating, and the variation in kind and scale of the many (often simultaneous) exhibitions held there over the years is immense. And yet these variations and mutual differences were effortlessly absorbed by the building. Time has demonstrated that the Kunsthal, maybe against all expectations, is a perfectly functioning building. Critics may carp about the unfindable entrance, the dauntingly raked floors or the steel grid floors nobody dares to walk on, but the Kunsthal works. If architecture is primarily about serving a function, then the Kunsthal is architecture of the highest order.

    That the Kunsthal is an extraordinary building, a turning point in OMA’s oeuvre and one of the icons of the resurgence of Dutch architecture in recent decades, is not at issue. So much was already obvious upon completion; the architectural reviews were almost without exception laudatory. But the main commentary then was not how extraordinary the architecture of the Kunsthal was, but how different. Now, twenty years later, one is struck primarily by how self-evident that architecture now looks, and how naturally the building has settled into its context. And that, too, is a virtue. If architecture, after the shock wave of the new has stopped reverberating, should stop proclaiming its radicalness and enter into a peaceable relationship with its surroundings, then the Kunsthal is architecture of the highest order.

    That architecture, the complex, layered composition of space, the clever routing in an endless loop, the skilful resolution of the different intersecting traffic categories (pedestrians, deliveries, roadway), the automatic integration of a Delta dike, the unusual (but meanwhile commonplace) ‘unmediated juxtaposition’ of ‘cheap’ materials: they were all favourably reviewed and rightly so. In fact there is only one aspect of the Kunsthal that has not received the attention it deserves: the structural engineering. One of the most fruitful collaborations between a structural engineer and an architect is that between Cecil Balmond and Rem Koolhaas. In nearly every one of OMA’s innovative designs – from the Sea Terminal at Zeebrugge, the Zentrum für Kunst und Medientechnologie in Karlsruhe, the Très Grande Bibliothèque and Jussieu Library in Paris, up to and including CCTV – a fruitful fusion has been achieved between space-form and construction. The Kunsthal was the first built result of this fusion. Balmond himself has dubbed the applied approach (for it is not a method), ‘informal’. He rejects the automatic assumption that a square box is best supported by a square Cartesian grid of columns. Orthogonal regularity is nowhere to be seen in the construction of the Kunsthal; every room has a completely different structural approach  and nowhere are things ‘just done the way things are done’. This aspect in particular contributed strongly to the multi-functionality of the rooms and the success of the building. Columns appear to have been placed at random and most are slanting, the rigidity of the steel roof over the main exhibition hall is achieved not with standard cross bracing; instead, it is provided with an ingenious horizontal arched structure and it is the odd combination of raked floor and perpendicular columns in the auditorium that provides rigidity.

    The integration of the construction is so self-evident and natural that in all those reviews of the Kunsthal scarcely anyone recognized its brilliance. An understanding of the load-bearing structure through an on-site inspection of the Kunsthal, should be compulsory fare for every student of architecture and structural engineering. If architecture is the self-evident integration of design and construction, then the Kunsthal is architecture of the highest order.

1) See Cecil Balmond: Informal, New York 2002. In this account of his ideas, Balmond discusses four different informal strategies that were applied in the Kunsthal: Brace, Slip, Frame and Juxtaposition.