Tensile moments

Once, it was going to take over the world. Lightweight architecture – tents, inflatables, suspension structures – came out of that whole Archigram thing of the Sixties through to the early Seventies, the beguiling notion that a building could be something other than a ponderously-assembled, supposedly permanent object in the landscape. Instead, it could look as ephemeral as its likely useful life. Five years, 12 years, even 25? At the time of the Beatle’s first EP, such time spans seemed way off into the future, and the future lay in impermanence.

Looking back now, you wonder why the revolution failed to happen. What mostly got built in the Sixties, after all, usually involved heavyweight concrete: with some honourable exceptions such as Cedric Price, Lord Snowdon and Frank Newby’s 1963 Snowdon Aviary at London Zoo. The enthusiasm for inflatables, for instance, quickly deflated. Dutifully, some architects produced them, usually for avowedly temporary buildings – Norman Foster’s blow-up office for IBM, say, and a number of low-cost sports halls – but, aside from periodic revivals for rock sets and performance spaces, you just don’t see them any more.

Tents have had a longer run, though again the high point was reached fairly early: in 1972, when the engineer Frei Otto and architect Gunther Behnisch stretched their undulating cable-net Plexiglass roof over acres of the Olympic village in Munich. After that, Otto’s dream of a suspended city no more got built than Archigram’s Bournemouth Steps of 1971 – a collision between something recognisably akin to the Pompidou Centre of the same date and an even larger series of tented spaces. Now comes a new book, Tensile Architecture in the Urban Context by Rudi Scheuermann and Keith Boxer – both of whom studied at Bath University under the UK’s king of tensile structures, the late Ted Happold. So: what happened to the dream?

Well, Michael Hopkins produced his chrysalis-like Schlumberger Research building in Cambridge in 1985, and never quite forgot it – the tensile fabric roof recurs in his work, most famously in his Mound Stand at Lords Cricket Ground (1987) but also as the entrance lobby of Glyndebourne (1994) and as the central public space of the Inland Revenue headquarters in Nottingham (1995), even as the canopy to his Buckingham Palace ticket office of the previous year – in all these cases as adjuncts to solid architecture, rather than as the main architectural event.

Then Ron Herron, ex-Archigram, got to build his famous Imagination Building in London’s Store Street in 1989. It wasn’t quite the insouciantly wrapped building of Archigram legend, since the fabric was not allowed (by fire officers) to stretch down the sides of the building as well as over its top – but it came close.

Oddly enough, it took people from outside the Archigram milieu altogether – architects Ron Arad and Alison Brooks, with engineer Neil Thomas of Atelier One – to get even closer to the spirit of casual enveloping, in the Chalk Farm studios of Arad and Brooks with their highly sculptural mesh-and-fabric roofscape.

Although Herron got to build rather purer (and smaller) tents in Japan before he died, the form was handled with rather more elan overseas. The Belgian architect/engineer Philippe Samyn’s 1992 M&G research complex in Vanafro, Italy, is a better example of the genre than Hopkins’ slightly fussy Schlumberger building, for instance, because it clads the whole building smoothly, like a huge hooped skirt. Renzo Piano returns at intervals to the tent, but nothing European can compare in scale with the marching tepees of Denver Airport, Colorado, by Fentress and Bradburn: or for that matter with SOM’s early Eighties Haj airport terminal in Jeddah.

Today, then, the tensile structure is just something in the armoury of all architects. It is no longer a manifesto statement, it is not new and exciting – it is just another form, there to be used when necessary. So young architects such as Lifschutz Davidson, becoming famous for their interventions on London’s South Bank, propose a series of canopies to span between their Oxo building and its landside neighbour. So BDP, which has seen more architectural fashions come and go than most, can roof its Eurotunnel terminal at Ashford in Kent with a giant tensioned fabric roof, complete with a tilted oculus of a skylight, and almost nobody notices. So Richard MacCormac, more usually known for his work in masonry, can briefly turn to the tent form when asked to design a playground shelter for an east London children’s school. And even when the spirit of Otto and Behnisch was evoked in the German pavilion at Expo 92 in Seville – a nostalgic return to the glazed cable-net structure, with a tensile flying saucer on top for good measure – that was not the building people talked about. Fashion had moved on to the timber temple of Tadao Ando, or the glass waterwall of Nick Grimshaw, or the organic architecture of Imre Makovecz.

The tent roof is seen as being good for grandstands, good for pavilions, good when diffuse light is needed over a wide covered area.

Happold and others were working on a return to inflatable structures for stadium roofs, but built examples are yet to appear. Despite advances in materials technology, clients are still wary of the cost implications of a covering that looks as if will need to be replaced at regular intervals. It has, in the end, become an architecture for specialised applications only.

It is true, and a bit sad, that the urbanistic qualities of the tent form have yet to be properly exploited in a big city. Hopkins’ plans to roof over the shopping streets of Basildon, for instance, never materialised. When you see the monumental rigidity of Richard Rogers’ wavy glass roof for the South Bank arts centre, you wonder why our newest architectural Lord did not consider the more fluid option of a draped tensile structure, which would have coped more easily with the lumps and bumps of Brutalism, and which would certainly have been a great deal cheaper, if less overtly magnificent.

The reason he did not is, I suspect, simple enough. True, the great tensile engineers Ted Happold and Peter Rice are dead, which must have taken a great deal of steam out of the movement. But beyond that, the world seems to want real architecture again. The public seeks at least the illusion of permanence, and so do architects seeking to build their monuments. What Archigram called architecture as an optional extra is just a bit too close to the bone for our tastes. A circus big top, we need no reminding, can be packed up and put away at a moment’s notice.

Tensile Architecture in the Urban Context, by Keith Boxer and Rudi Scheuermann, is published by Butterworth Architecture, 45.00.