Architecture: The outer darkness

Nimbyism is a trying condition, taxing the boffins at the Science Museum in London. Their director and trustees have commissioned and planned one of the most exciting new museum wings in Europe. Funding is firmly in place. What seems like a perfect site - a largely vacant back yard behind the existing museum buildings in salubrious South Kensington - is there for the taking. The architects' drawings are all but complete and the engineers and contractors are champing at the bit, confident of completing what will be known as the Wellcome Wing in time for an opening in 2000. As many as two million people a year, 300,000 children among them, are predicted to ogle this radical building and the ultra-modern treasures it will put on show.

We do not, however, live in a perfect world; "E" might well equal "mc2" in the scientist's equation chalked on a blackboard, but the Wellcome Wing is having difficulty fitting so neatly into the site tailor-made for it. The problem facing the museum and its architects, MacCormac Jamieson Prichard, is a simple one, the sort that would be either ignored or quashed if London was Paris, which it isn't.

Speaking on behalf of the anonymous residents of 169 Queens Gate, a grandiloquent block of late Victorian mansion flats, the planners of the Royal Borough of Kensington & Chelsea have put a spanner in the works of Richard MacCormac and the Science Museum. The big question is whether the spanner can be removed, with the agreement of all parties, and work can start on the Wellcome Wing.

One of the joys of what passes for democracy in Britain is that local residents can fight successful actions against monstrous development schemes and have a good chance of winning. This is the ancient story of David taking on Goliath, the little man fighting the bully whether the latter wears a suit of armour or, more likely today, a neatly-pressed Armani suit and a cheesy smile created for him by a spin-doctor. In Britain we are famously sympathetic to the cause of the underdog. But, where does fighting the good fight in planning terms become no more than Nimbyism?

In the case of the Wellcome Wing, the "not in my back yard" tendency appears to have come to the fore. Its case on the level of daylight available in the narrow brick gulley that separates the lavatories and bathrooms of 169 Queens Gate from the Omani embassy next door. Should the Wellcome Wing be built, there is a vague possibility that some of this daylight may be spirited away from a number of windows by the shadow of the new building. The staff of the Omani embassy who will overlook the Wellcome Wing directly have expressed great enthusiasm for the new venture, knowing that it can only enhance a site that has been left all but derelict for decades. Not only will a superb new building be erected here, but there will be public gardens and a sensitive new residential building, also by MacCormac Jamieson Prichard, fronting Queens Gate.

Should the Wellcome Wing be delayed, the museum stands to lose pounds 150,000 a month in inflation costs alone while a solution is reached. Should it be dragged to a halt because of a potential loss of daylight (a very small loss) to six or seven bathroom windows, we all stand to lose. It is important here to explain what is at stake. The illustrations on these pages go some way in revealing the quality of MacCormac's design.

The new wing was first mooted by the Bell Committee of 1911 (yes, 1911 - this is England), but it was not until 1995 that the Wellcome Trust offered the museum a grant of pounds 15m (later increased to pounds 16.5m) as a major contribution towards the cost of a new gallery devoted exclusively to the display of contemporary science, technology and medicine. A year later, the Heritage Lottery Fund underwrote the project by offering the museum a grant of pounds 23m.

From the outset, the Wellcome Wing was to be no run-of-the-mill extension. "Science", says Sir Neil Cussons, the museum's energetic director, "is marvellous and surprising, so our intention is to create a new wing which is amazing to visitors and engenders a mood of heightened expectation, a theatrical experience in which the drama is both the building and its scientific contents."

This drama will be entered through a new exhibition, "Making the Modern World" and under a 450-seat Imax science cinema suspended overhead. The cinema, a dramatic experience in its own right, will go a long way to pay for the running costs of the new wing. As visitors move into the main space, a kind of fin de siecle cathedral of science, they will gawp at three exhibition floors that will appear to float unsupported in space, and be back lit by ethereal walls the colour of the sky at night. Stairs and catwalks leading up to the three galleries will also appear to be suspended, as if by magic (or science): here is a building that comes close to being "virtual", as much tangible as intangible. How are the galleries supported? Where do the walls begin? What are they made of?

The idea is that the building and not just the exhibits is to be experienced as a scientific marvel. It will appear to have no certain or finite limits. There will be no daylight, or at least not in a conventional sense. The end wall facing 169 Queens Gate and the Omani embassy will be clad in a deep blue glass.

Apart from being theatrical and potentially rather beautiful, the Wellcome Wing will give the museum resources equivalent to those of comparable international institutions (and rivals) such as la Cite des Sciences et de l'Industrie at La Villette, Paris, the Deutsches Museum, Munich, and the Smithsonian Institute, Washington. Above all, it will be enjoyed by millions and respected by nearly everyone.

Those residents at number 169 peeping out from their bathrooms in the morning will overlook a special building and new gardens in the knowledge that their generous complicity, should they give the new wing their grudging blessing, will have made millions happy and for a long time to come.

If they stick to their guns and force the museum to fight through the treacly world of planning inquiries and appeals, money, time and goodwill will be squandered and the chance of having a special building devoted to the understanding of science possibly lost.

It may well be that boffins on the registers of the Science Museum will be able to prove that those windows at 169 Queens Gate will not lose the daylight residents rightly cherish, or will even find ways of re-directing daylight their way. If they can't, then perhaps residents can be soothed with free season-tickets to the Science Museum. Or, perhaps the architects can redesign their bathrooms and lavatories for them in splendid style and fine materials. A solution, however, needs to be found and found soon. Our new-found suspicion of science, our predilection towards mediocre science education and our churlish dismissal of progress are inner demons we must fight. Another is Nimbyism. Nimbyism is a powerful force; can science yet bring it to heel? As the key planning committee meeting takes place next Monday, we will soon find out.