Material assets: huge opportunities are offered by an increasing range of materials but their essential sensuous importance remains.

From time to time, materials and materiality are of little overt importance in architecture. In the second half of the eighteenth century, for example, architects' drawings rarely indicated materials to be used (though they were presumably specified elsewhere). Even window glazing bars, elements that do so much to give the detailed scale of Palladian and Neo-Classical architecture, were usually omitted from elevation drawings. Sections rarely show what buildings are made of. Details (of the outside at least) are rare. From the drawings, buildings could be made of anything from icing sugar to mud.

Of course, they were not, and most of them have great material presence. Materials were usually chosen on economic grounds. Transport was a major element in material costs (1) so, for most buildings, local sourcing of materials was vital, from the very site itself if possible. So there was an often unarticulated agreement between builders and architects (where they were involved) to use tried traditional techniques. Hence the congruity of scale, texture, proportion and form of most buildings in traditional European villages, derived from native sources as different as the timber of mountain regions to the clays of flood plains. The only exceptions were grand buildings for the rich, for religion or the community. Though these were often larger developments of the vernacular, sometimes huge components were transported for long distances to add grandeur. Technologies used to transport such big objects were very similar to those used by the ancients, who from Stonehenge to the Roman Empire had learned how to haul huge pieces of stone over astonishing distances.

The great nineteenth-century constructional revolution

Even so, congruity (with a little highlighting of the rich and powerful) was the rule until the end of the eighteenth century. Yet today, without fierce preservation and planning regulations (and sometimes poverty), such congruity would have disappeared long ago. By the middle of the nineteenth century, new forms of mechanical production and bulk transport (canals, then railways) radically altered the availability of materials, allowing Welsh slates and Italian marble. Scandinavian timber and Belgian glass to become part of the palette of almost every architect in the industrialized world.

In response, the theory and practice of architecture changed radically. By the mid-nineteenth century, drawings showed every flashing and drip, practically every nail. It was a remarkable irony that Pugin and his Neo-Gothic followers, who believed so passionately in truth to materials and trying to get back to the ideal of the free medieval craftsman, so often designed in a way that gave builders much less freedom than they had in Neo-Classical times.

The distinction between Neo-Goth and Neo-Classicist continued throughout the twentieth century. Many early Moderns were happy to imitate the simplicity of poured concrete planes in masonry and stucco; like the Neo-Classicists a century earlier, they were concerned to achieve forms and spaces with not much regard for the materials from which they were made. Before the Second World War, Le Corbusier was at least partly a member of this group (his later conversion to expressed poured concrete came after examination of the slave-made structures of the Nazi Atlantic Wall). At the same time Aalto, the Neo-Goth, was exploring the place-making potential of brick, bronze and wood in applications old and new.

Today, the distinction continues. In his fine posthumous analysis of the nature of design, Michael Brawne declared that, 'when I am considering the design of a building, I need at the outset, or at least very soon after, to be concerned with the selection of materials to be used in construction. This is especially true for those materials which will have an influence on spatial organization and appearance ... This is unlike, say, the choice of the damp-proof course. In varying degrees materials are of necessity part of architectural thought'. (2)

On the other hand, much contemporary architecture seems to be made by organizations and systems who could not care less how it is built. Much everyday architecture (at least on the European continent) is created out of stucco on insulated blockwork walls. They could be made of anything, anywhere, and the only means of giving them empathic or tectonic qualities is by carefully introducing reassuring elements in the parts you can touch, like the joinery and ironmongery. Much high profile architecture is created by superstars who often seem to be indifferent to what their work is made of, as long as it looks arresting on the pages of glossy magazines.

Atavistic and sensuous memories

One of the reasons that the nature of materials affects us all is because they evoke atavistic memories through senses other than vision: touch, hearing, smell and even taste. Perhaps this is why, as Richard Weston observes, building has been a conservative and tradition-bound business 'for the most part ... at least when compared to many other aspects of human endeavour. The means of production have changed out of all recognition, new materials like steel and reinforced concrete have been introduced, and old ones such as glass produced in sizes and quantities previously unimaginable'. (3) But 'when new materials have been introduced, they have generally been used in emulation of familiar modes of building'.

I suspect that this analysis is rather exaggerated when considering contemporary architecture. Over the last century, building materials have become increasingly stiff in relationship to weight. Partly because of that, and developments in plastics, glass, metals and thermal insulation, building components can become thinner and lighter offering new building possibilities, particularly off-site prefabrication, now so popular with well-meaning commentators on building processes and increasingly by architects and builders themselves. (4)

[GRAPHIC OMITTED]

[GRAPHIC OMITTED]

Amazing adhesives have made possible new conjunctions of materials, components in which what you can see and touch is a thin skin over back-up substances. But such technology does not necessarily prevent the finished result having the sensual qualities of solid materials. In a sense, the techniques are at least two millennia old. We do not know exactly what great Roman buildings such as the Pantheon and the Baths of Caracalla looked like but their claddings of thin marble and metal sheets were presumably manufactured off-site and transported to cover and haptically transform the huge masses of masonry.

At the Getty, Richard Meier evoked ancient technology (AR February 1998). Clients and local residents objected to the architect's usual metal panels. So he chose travertine, that immemorial material, still quarried near Rome. The stone slabs were made by a new technique in which a special guillotine was developed to give them a riven surface, restoring to travertine, so often debased in the foyers of flashy hotels, noble visual and tactile qualities: returning it to the dignity it had in ancient times. (5) Even masonry can be prefabricated: the brick panels of the Inland Revenue building by Michael Hopkins (AR May 1995), which are used to give the building thermal mass, were made in a factory and hoisted into place on site.

But if new technology does not preclude traditional sensual qualities of materials, it can certainly transform them in some applications. Weston points to the emergence of 'composite forms such as carbon-epoxy-reinforced wood, resin mortars and super-high-performance concretes ... while nano-technologies, working at the molecular scale, promise materials tailor made to specific needs--reversing the traditional sequence of decisions in choosing a material. Even the most ancient, such as stone, can be "improved" by the application of ... bacteria, which synthesize calcium carbonate to form a hard, naturally protective coat'. (6)

Such techniques and materials will undoubtedly greatly influence buildings in future. The imperative to generate buildings that exist in greater harmony with the planet will necessitate the use of many innovations in materials. But in the process, we must not lose understanding of the immemorial empathic relationship between humankind and the materials with which we construct architecture.

1 See for instance Hollingsworth. Mary, The Cardinal's Hat: Money, Ambition and Housekeeping in a Renaissance Court. Profile Books, London, 2004, p148ff. Hollingsworth looks at the costs of bulk transport in the Povalley by analysing the account books of Renaissance grandee Ippolito d'Este.

2 Brawne, Michael, Architectural Thought: The Design Process and the Expectant Eye, Elsevier, Architectural Press, 2004 Amsterdam etc, p125.

3 Weston, Richard, Materials, Form and Architecture, Laurence King Publishing, London, 2003, p15.

4 Kieran, Stephen and Timberlake, James, Refabricating Architecture, McGraw-Hill, New York, 2004.

5 Brawne, op cit, pp49-51.

6 Weston, op cit, p119.