Six prototypes of the two-classroom units, looking more like a Star Trek flotilla than traditional school buildings, will be installed - the Millennium Fund and other purses willing - at a London school by the turn of the century.

The buildings are the result of a competition between five leading firms of architects to design an adaptable modular classroom. The competition was run by the governors of Westminster’s Hallfield school, whose airy green campus in the heart of London is regarded as a triumph of 20th century primary-school architecture and landscaping. A product of the architectural flowering of the 1951 Festival of Britain, Hallfield still attracts international acclaim and is a starred Grade II listed building.

Over the years the school has grown as a result of an influx of homeless and refugee children that has doubled its numbers; with the roll nearing 700, the governors have for some time wanted to replace the block of leaking portable cabins that mars their campus with

purpose-built classrooms to match the rest of the school. But they were keen to keep the flexibility of portable buildings and avoid the disruption of a major construction programme.

The governors decided that their need for high-standard accommodation which could be quickly adapted to reflect changes in class size or in the school roll was shared by schools throughout Britain and, indeed, the Continent; and that this need was likely to shape school construction in the years ahead.

So they came up with the competition for the design of “the Hallfield Prototype”-a classroom that would not only suit the Hallfield campus, but could be customised to meet the needs of other schools here and abroad. The buildings would need to be modular units so they could be built in stages.

The brief stated: “The governors believe it is imperative that teachers and children are provided with modern classrooms designed to aid and encourage modern methods of teaching, provide IT facilities, and have the flexibility to grow and meet the likely demands of the 21st century. The units are to provide a model and set the standard of school buildings for the 21st century, and in their design harmonise - and, as it were, hold hands - with one of the very best examples from the 20th century.”

The winning design, from Future Systems, the London team responsible for the futuristic media centre the MCC is to build at Lord’s cricket ground, is for a factory-built concrete and glass unit that can be mass-produced and erected or dismantled in a matter of weeks. Consisting of two semi-circular classrooms with a walled cross-section between them containing storage and display space and a teachers’ cloakroomWC, the units will be cabled for computers at each desk, and have an innovatory energy-saving heating and ventilation system, and natural or fluorescent lighting diffused through a concave fabric ceiling. They will be configurable to provide one big room or several classrooms for small-group teaching.

The units, whose roofs can be colour-coded to identify their function, are described by Future Systems as “little pavilions for little people”; they can be joined by tubular glass walkways to a cloakroom unit, to each other, or to existing school buildings.

The man who designed Hallfield, Sir Denys Lasdun, is unstinting in his praise for the design. “It’s a thoroughly modern approach which takes school design forward but fits in with the existing buildings,” he says. Lord Rogers, the world-renowned architect who helped Sir Denys to judge the competition, shares his enthusiasm.

Judith Minton, about to retire after 25 years as head of Hallfield Infants, says the design of the new classroom recognises, like Lasdun’s masterpiece, the enormous difference that a light and airy environment can make to children’s progress and behaviour. “That’s what has made Hallfield such a wonderful place to teach in - the children are always aware of the world just outside the classroom and love having it there. We have never had vandalism or graffiti; the children are fiercely

protective of the school and the grounds and get very angry if they find a single daffodil has been broken.

“My staff and I will be wanting some modifications, but that will provide useful experience in customising the classrooms to meet a school’s own ideas and requirements.”

Sandy Crawford, the chairman of governors, says the rigorousplanning criteria ensured that the design would be of high visual and aesthetic quality. “We realised that if it was good enough for us it would be more than likely to enhance most primary campuses and set the standard for new school construction,” she explains.

Hallfield’s governors are planning to launch a public appeal for funds as well as seek grants from the Lottery Commission and other public sources.

Future Systems says that despite the relatively high cost of the prototypes - #163;80,000 for one classroom - large-scale production should make the units competitive with conventional construction; the units come with built-in facilities and should be considerably cheaper to run.