Aluminium Imagination Architectural Awards:

Winner of the pounds 10,000 Aluminium Extruders Association (AEA) First Prize NATWEST MEDIA CENTRE, LORD'S CRICKET GROUND Architect: Future Systems

THE FIRST all-aluminium, semi-monocoque building in the world will take a lot of photo calls, because it is the NatWest Media Centre at Lord's Cricket ground, and the eyes of the world are currently upon it.

The plasticity of aluminium allows the double curvature of its pod-like form. No other material could have achieved this: steel would have been twice as heavy and impossible to suspend so lightly upon a cement stem. A composite construction, although significantly lighter, would have almost doubled the construction costs.

Future Systems, the architects of the centre, looked to the Pendennis boat builders in Falmouth and in Rotterdam to construct the membranous aluminium shell that sits high above Lord's cricket ground like the eye of a camera. The imagery of a camera, a boat hull, state-of-the-art sports equipment, and the curves of the Lord's Ground all inform the design, yet as the architects point out, "The NatWest Media Centre is not a boat or a car or even a building as we know it. Rather, it is an object suspended in space."

The series of aluminium ribs and spars welded to an external plate skin - a technique used in the boat building and aircraft industries to make watertight membranous shells - is known as monocoque construction. The curves are stronger than rectilinear structures. The Future Systems building is only semi-monocoque because it is wrapped in insulation to meet fire regulations. A second layer of foil-backed insulation allows the use of single glazing without compromising the thermal performance of the building. Twenty-six sections of various sizes were prefabricated off site, brought up by road with police escorts, craned into position and then welded. But whereas boat hulls are constructed upside-down in a boatyard, this building was assembled 15 metres in the air, cantilevered from concrete columns above Lord's. Inside the concrete stem, lift shafts whisk cricket commentators into the cool blue aluminium-lined interiors, which were inspired by a Fifties Chevrolet.

Because Future Systems are keen to champion the use of aluminium, they were careful to address the environmental issues implicit in the structure of the shell, which was made entirely from aluminium sourced in France and Switzerland. Although it requires a great deal of energy to produce aluminium, it is fully recyclable, and its strength-to-weight ratio results in a highly efficient structure. Since aluminium is non-corrosive, Future Systems finished it with a yacht-specification paint in glossy white to give a durable and maintainable finish.

The site is as important to the architects as the method of construction and the materials used. As Future Systems' competition report from 1995 says: "Our objective was to respect and savour the essential nature of Lord's at the same time as creating a building that will come to symbolise the most sophisticated and beautiful media centre in the world." The arrival of two new stands - the Mound Stand and the Grand Stand - shifted the main axis of the ground away from the pavilion. The siting of the media centre opposite the pavilion redresses that balance, while the soft curves of the building's form reduce the volume of the building to a minimum.

The building faces due west. The glass facade, which is set at a 25-degree incline, provides the occupants with clear, unobstructed views of the game without creating glare or distracting reflections for either players or spectators.

The judges were unanimous that this ground-breaking design for Lord's Cricket ground was to be the winner of this prestigious award. However, news last week that the man who commissioned Future Systems' media centre, Brian Thornton, quit over the cost of the building, illustrates that all great architecture is not without its price.

Thornton, who was chairman of the estates committee at Lord's - an honorary post - tendered his resignation at the MCC AGM. Two years ago he told the MCC that the building's cost would not exceed pounds 3.5m; it eventually cost pounds 5.8m. Thornton told Building Design that it was "a matter of the degree of the over-run. The huge difference meant that responsibility had to be taken by someone. I led the MCC into doing it."

Taking comfort from the fact that he has championed one of this century's best buildings in Britain, he told Building Design, "I am absolutely delighted and thrilled with what has been done. I will be judged by the results, and people will eventually forget about how much it all cost."