MATERIAL WITNESSES.

Architecture's relationship with materials is complex and immemorial. Historically structured by technical advances and invention, it is also dependent on sensory qualities and how these colour human perception.

Viewed as servants of form and allies of structure, materials have received only cursory attention in the history of architecture. True to Platonic precepts of matter's inferiority to form, this history is traditionally recorded as a primer of signs, geometry, proportion and decoration. For the most part, materials remain silent witnesses, occasionally lined up for prosaic dissection in construction textbooks. Yet from wattle to neoprene, the history of architecture is also the history of material invention. Discovery of new materials, or new ways of working or combining existing ones, have marked hinge points in architecture's evolution, suggesting new possibilities and the generation of new forms.

Before global industrialisation, limitations of transport, labour and technology ensured the continuity of a vernacular architecture based on local materials taken from or made in the immediate vicinity. Timber was felled from the nearby forest, bricks baked using local clay, stone cut from a convenient quarry, sustaining a building culture with an umbilical connection to place. This link between arte-fact and the earth from which it grew was not merely an economic imperative, but also satisfying at a psychological level.

As increased industrial efficiency drove down production costs, interest in developing new and more widely available materials was aroused. The first iron bridge at Coalbrookdale was built at exorbitant cost, but proved the harbinger of iron as a cheap and universal building material. At the beginning of the century, aluminium was extracted by chemical means and was more costly to produce than gold. The discovery of coke-based smelting for iron, electrolytic extraction for aluminium and the float glass method of manufacturing plate glass all reduced the cost of producing such materials to acceptable levels. Allied to the growth of mass transportation, this meant that many different sorts of non-indigenous materials could be easily moved around, so severing geographical and psychological links between locality and building.

Now both the technology and the will exist to transcend, often bizarrely, the innate properties of most building materials. Metal is deformed into increasingly curious and convoluted shapes, glass is used in compression, stone exploited in tension. Through investigation in the fields of biology, aerospace and automotive engineering, the wonder and sophistication of natural forms is being revealed, with consequent effects on the demands made of materials. Recent research has also given rise to notions of 'biomimicry': of buildings that are not just static enclosures of space, but attempt to emulate the responsiveness of living organisms.

It is safe to predict that we will continue to unravel the technical qualities and capacities of materials, but our own responses to them are perhaps more complex, deeply rooted and difficult to divine. Materials embody both a physical and perceptual alchemy. In physical terms, raw matter is transformed by the effect of heat, chemicals or other generative processes. In experiential terms, materials are endowed with meaning, and can evoke feelings, trigger connotations and address the deeper levels of our understanding. A material can become the scapegoat of unpopular architecture, as concrete, for instance, is now invariably associated with the physical and social failings of Modernism. Conversely, it can also be used to legitimise buildings of dubious distinction, such as the thin veneer of stone used to clad banal office blocks for the purposes of crude capitalistic aggrandisement. Applied in such a mendacious way, the material is effectively robbed of authenticity and meaning.

To build quickly or formulaically generally entails the debasement of materials, with a resulting sensory impoverishment. Materials have particular qualities and buildings often take years to make. Both are profoundly altered by the passing of time. As Juhani Pallasmaa postulates in his densely argued discourse for a tactile, multi-sensory architecture (p78), this slowness and mutability is fundamentally at odds with the increasing ephemerality and transience of an information and sense-saturated world. Immaculately choreographed images of architecture perfected and frozen at the moment of its creation exist in a necessarily timeless vacuum. The impact of the subsequent processes of ageing, weathering and traces of use are regarded as inherently negative. As Pallasmaa makes clear, materials can speak evocatively and even pleasurably of the passing of time - stone of its geological origins, brick of fire and earth and ageless construction traditions, metals of ancient casting processes and the patina of age, timber as a once-living tree.

Pallasmaa's arguments for hapticity and slowness might seem optimistically at variance with the fast, superficial way most buildings are made these days, but they do strike a much-needed, elemental chord. Some of Pallasmaa's tenets are embodied in the recent work of Peter Zumthor, whose artisanal origins have nurtured a deep understanding of the nature and language of materials. Zumthor's reflections are also tempered by sensuous experience of the world - by sight, touch and smell. 'I see the rusty metal of the door, the blue of the hills in the background, the shimmer of the air over the asphalt... Everything I see, the cement slabs that hold the earth, the wires of the trellis, the chiseled balusters on the terrace, the plastered arch over the passageway - they all show traces of wear, of use and of dwelling. And when I look more carefully, the things I see start to tell me something about why, how and for what purpose they were made. All this comes to light, or is concealed, within their form or presence. .. I like the idea that the house I build contributes to the atmospheric density of a place, a place which its inhabitants and passers-by will remember with pleasure'. [*]

Putting materials to best use involves an appreciation of their innate sensory qualities as well as their technical potential. The buildings in this issue attempt to demonstrate this investigation and invention. Rafael Moneo's Kursaal auditorium in San Sebastian (p44) has a translucent glass skin which changes and shimmers like a chameleon in different climatic conditions. Zvi Hecker's Palmach Museum in Tel Aviv (p50) uses lowly limestone dug from site to forge a resonant geological connection with building and place. Meili & Peter's college for Swiss woodworkers (p67) ingeniously confounds traditional expectations of timber buildings and Caruso St John's new Walsall Art Gallery (p62) embodies a heightened awareness of the nuances of materials used simply yet rigorously. Such explorations provide some hope of being able to create architecture that is not only sensuously and psychologically rewarding in itself, but which retains some authenticity and 'atmospheric density' in a world of increasingly manipulati ve fictions and insubstantiality.

(*.) Peter Zumthor Works, bars Muller Publishers, Baden, 1998, p8.