One of architecture's more enduring conceits is that it can adequately represent the entire space and time of Creation. But when 10,000 new species are being named every year - at which rate it will take up to three millennia to classify the 30,000,000 waiting to be discovered - and space and time expand at something like the logarithm of the integral of x to the power of n phi beta kappa (not forgetting the dx), even the most potent numerology and erudite classical decoration are of little use.
That, in a nutshell, is the problem which faced architect Philip Wharmby of Wharmby Kozdon, in designing the 1500m2 Millennium building for London Zoo, which houses the Web of Life exhibit. We should be careful about casually using linguistic metaphors about shells; the Web of Life curatorial- and-keeping team is probably at this moment engaged in a research programme for isolating the shell's gene pool, breeding them and eventually releasing them into the wild, as it is with the otherwise extinct Partula snail.
The 'web of life' concept recalls the old, pre-Darwinian idea of the Great Chain of Being, connecting primal sludge to angels through plants and animals. Replacing the static and restricting chain with the living and fragile web, it deals with the inter-relationships of such trivia as the Partula snail - 'everything from ants to anteaters', in the words of head invertebrate-keeper Dave Clarke - which add up to the extraordinary biodiversity keeping us all alive. One of its themes is echoed in a comment from a Harvard professor that if people were not so impressed by size, they would find an ant much more interesting than a rhinoceros. The web idea is a new concept in zoo-keeping with a far wider range of animals than usual, confirms Clarke. Wharmby Kozdon's masterplan was produced in the light of the zoo's soul-searching after repeated threats of closure in the early 1990s, and there is a commitment to openness and accessibility. Lying somewhere between a traditional zoo and a museum, the zoo's design has to make biodiversity interesting to the million or more people who visit the zoo every year, and to provide facilities for research.
The Tamil-speaking elephant keepers (who speak Tamil because it is necessary to bond with their charges) would apparently demolish the Casson elephant house because it solidifies an old-fashioned idea of animal husbandry. Apart from this feeling of a negative sense that the zoo already had 'too many monuments' - and the vague sense that the new building should turn outwards rather than inwards - there were few architectural leads. Indeed, Wharmby suggests that having no preconceptions about zoo architecture was a major factor in the partnership's appointment. Its initial masterplan broke down what the administration had seen as a huge and intractable £40-million maintenance problem into a programme of measurable goals. Two early ones, the children's zoo and the camel house, respectively gave opportunities to bring coherence to a group of disparate new and old small buildings, and to develop an elemental architecture of post, beam and wall which allows views between the zoo and Regent's Park - successfully, except, as Wharmby confesses, the camels tend to eat their building.
By the time he started on the Web of Life building, Wharmby had some idea of the background and personalities, but no pat solutions. In any case it was altogether more complex than either of the earlier designs, needing to house exhibits, visitors and staff. The design composition is simple: a large oversailing roof resting on regularly spaced columns, forming a V-shape on plan. This is an architecture of openness, as if the ground has inflated to form a space underneath. Glass walls reinforce this sense, fulfilling the desire for visibility but adding to the difficulties of environmental control. At each extremity is a small animal enclosure, containing butterflies, Javan starlings and lemurs, emphasising the reversal of typical zoo architecture: less enclosure and public space or 'inside and outside', more interface between animals and people. The main facades have an austere discipline - austere, at least, to the extent that the pipes, lettering and other add-ons allow.
Wharmby happily admits that the interior is barn-like, not unreasonable considering that it houses animals and that the building has a longer lifespan than the exhibition. The inside should feel like a large, open space, with the curving roof and a sloping floor level - staff occupy a mezzanine above the lower corner - but is slightly compromised by the exhibition layout. The exhibition implies a directionality in a building which should be open, and confines visitors to the perimeter. At its best, it does allow glimpses into the breeding rooms and spaces where keepers work on their stud books, recording, amongst others, the 52-million-year- old undiluted dna of the Partula snail.
Detached from the main structure, but with approaches equally sheltered by its projecting canopy, are two smaller spaces with a very different, cave-like character. Limestone-faced, they are covered with earth and form the wcs and an activity space for children; one with views through a rooflight to the wallaby enclosure and the other through a porthole into the ant-eaters' den. Their earthbound nature and the expansiveness of the main building with which they form an entrance courtyard, make a metaphorical section through the zone above and below ground where animals live. It's all about trying to change the expectations of such spaces, and to remind visitors where they are.
Changing expectations about normal habitat underlie the mission of the Web of Life. Public access to zoos started as a kind of freak show, dependent on novelty. When scientific purpose started to inform them in the nineteenth century, their layout derived from the rigidities of Linnean classification, with nature's separation of species matched in discrete enclosures for each animal. Darwin's evolutionary theory licensed a pseudo-realism which first found expression in the Mappin Terraces and lasted right up to the 20-year-old big cats enclosure. Its layout almost allows one to believe that the animals can mingle with each other and engage in some form of natural selection.
It is notable that both of these earlier paradigms had some affinity with an architectural counterpart. Classicism suggests a social order where everyone and everything has its place; Darwinism is not wholly unconnected with architectural determinism. But what clues might there be for the Web of Life? They are, suggests Wharmby, more elemental and abstract. 'I like things to have a certain integrity,' he explains, remembering long debates in the office as to whether the columns should be timber- clad. He also enjoys using certain materials. 'I love Corten steel,' he continues about the roofing sheets. 'It's very forgiving and acquires a patina of age very quickly.' Short spans appeal to him too; he likes to use intermediate supports to articulate a space.
Ecological thinking is another obvious affinity between architecture and the Web of Life. If anyone should be concerned about the natural environment, says Wharmby, a zoo should be. So all the materials are easily sourced. A much stronger contribution to the building's architectural character comes from the heating and cooling strategy: concrete floor slabs at ground level and for a small mezzanine give some thermal mass, while the insulated roof and thermal blinds exclude excessive heat-loss or gain. A heat exchanger recycles energy from outgoing stale air into incoming fresh air during cold weather, while warm-weather cooling is aided by using the large chimney extractors and water at a constant 12degreesC supplied from a borehole.
It took a millennium or two for architecture and philosophy to coalesce in expressing the Great Chain of Being in Gothic cathedrals. Here, and perhaps with a subtle subliminal symbolism through funding from the Millennium Commission, architecture becomes a modest but active and integral part of the Web of Life.