How architects think

What the architects Herzog and de Meuron call ‘the waste products of a thought process’ are set out on tables and stacked against walls at Tate Modern until 29 August (the transformation of the Bankside power station into Tate Modern was Herzog and de Meuron’s work). A video projection gives you a notion of what it is like to walk round and through a number of their finished buildings. For the rest, you are offered chunks of roughly carved foam, models in cardboard, wire-mesh or wood, samples of wall finishes, etched concrete slabs, glass light-fittings, drawings, photographs and so forth. The things on show were created to assist the visual exploration of architectural ideas. Unlike professionally made presentation models, which are detailed, often flimsy and tend to play down sculptural qualities, most of the models here are sketches in three dimensions: solid, simple reductions of complex structures, things which try out an idea rather than represent a building in miniature. Some samples of materials and mock-ups of details (the biggest is a section of the web of girders that will enclose the National Stadium in Beijing) are life-size, so the scale of details and the texture of surfaces – the hardest thing to model convincingly – are registered. The whole affair is exhilarating; these ‘waste products’ take you close to the processes of the trial, error and tested variation which carry an architectural idea forward from its beginnings on the back of an envelope to its final realisation.

You get another angle on how architects think in the exhibition of architects’ drawings from the Barbara Pine collection, at Sir John Soane’s Museum until 27 August. The most interesting and liveliest are sketches which take you close to the moment of invention. These, like the material at Tate Modern, are early moves, unresolved and sometimes tentative. Frank Gehry’s 1982 ‘Study for a Tract House’, shown here (it was made for an exhibition not a client), is on the face of it no more than a doodle in brown ink and coloured crayon. But its sprightliness sums up the spirit which, in finished buildings, so undermined their seriousness that Gehry, along with a few others, was able to do what no one had done since 18th-century gardeners threw in the odd grotto and hermit’s cave: make architectural jokes. The hesitation and overdrawing of a large, very rough sketch by Louis Sullivan allows you to watch him feel his way towards a plan and elevation for the Babson house. By contrast, the neatly finished perspective drawing from the office of his pupil Frank Lloyd Wright, showing how the Johnson Wax building would look when the tower was added is now less interesting than a photograph of the finished building – though it may well have been useful for the client. One of the Futurist architect Sant’Elia’s sketches of ziggurat-like blocks is a reminder of how little you have to build to gain a reputation and be an influence: he was only 28 when he died fighting in 1916. He was not without followers; you can get a good idea of how his drawings would have translated into buildings from the Brunswick Centre in Bloomsbury.

Another example of how an architectural reputation can be sustained by ideas – in this case not even graphic ones – and only a minimal amount of building is on show at the Design Museum until 9 October, where there is a display of the work of Cedric Price, who died in 2003. Price suggested that ‘the real definition of architecture is that which, through natural distortion of time, place and interval, creates beneficial social conditions that hitherto were considered impossible.’ It is not surprising, given this idea of the architect as facilitator rather than monument-maker, that there are more sheets of typed notes and diagrams here than records of structures. In Price’s case, the ratio of influence to real buildings was about as high as you can get: the only major work his name is attached to is the aviary at the London Zoo, yet the ideas he and Joan Littlewood developed around the Fun Palace project prefigured and influenced the Piano and Rogers design for the Pompidou Centre. He also suggested the equivalent of the London Eye in a study of what might be done with the South Bank long before the millennium.

All three exhibitions support the thesis that architecture can be enjoyed as a mind game in which the experience of actual sites does no more than test what has already been built in the imagination. It’s a game which discounts the scale, solidity and presence of real structures, yet in fictional buildings, as in fiction itself, we can enjoy vicariously things we would as soon stayed unrealised. When Claes Oldenberg started to make real giant lipsticks rather than just present them as projects in drawings, witty ideas became ponderous jokes. The sense that what is imagined can be as exciting as anything built pervades the Herzog and de Meuron display. A side effect of the generous insight they give into their way of working is to make intermediate stages more interesting than end results. I would like to see some of the actual buildings, particularly the art galleries, which the video projections suggest are magically calm and good to the work they contain: the exhibition makes me feel better about Tate Modern itself.

The buildings that one feels can only be properly known in the flesh, bear the marks of the lives, work or ceremonies which they enclose. Much of the hopeful architecture of the 1950s and 1960s – much of 20th-century Modernism altogether – was labelled with slogans which, like Price’s claims for short-term, flexible structures, privileged users over designers. The assumption was that a building – a school, a block of flats – became interesting because of the things done in it and to it. The ultimate model was something like the Eames house in California: a factory structure that was brought alive by the furniture they designed and the things they collected.

The architects of the last decade or so whose profiles are highest – Libeskind, Hadid, Gehry and, closer to home, Will Alsop – offer buildings that draw attention to the design; the visitor can feel more like an audience than a user or resident. Herzog and de Meuron have made their contribution to this kind of high-architecture graffiti, but they have also put together buildings like the Dominus winery in California. It is structurally dramatic (the façades are faced with gabions – wire containers filled with rocks), but very simple and very kind to the landscape. Their expressed intention is to make designs which grow out of clients’ needs. The results are thoughtful, complex and worth thinking about. One thing the Tate display of their origins brings home to you is that architecture, always a conceptual art, now more than ever seems also to be an ephemeral one. In the buildings that win international prizes and make international reputations, the distinction between architect and set-designer, between building as structure and building as message, has become as vague as it was when Inigo Jones created masques as well as banqueting houses and palaces, all of them as projections of the king’s power.