Architecture: Model city built from a few humble cigar boxes: Havana

Architects in Havana are short of money, earning on average about 400 pesos, or dollars 6 a month at the current rate of exchange. They are also short of materials and technology, but they are far from bereft of ideas. Certainly the team of architects, engineers, planners, computer experts and sociologists who form the Grupo para el Desarrollo Integral de la Capital based in the tree- lined Havana suburb of Miramar is neither waiting for a Cuban apocalypse, nor planning to sail to Miami.

Havana is its long-term project and its ideas include some of the most advanced thinking on the future development of cities to be found anywhere.

This semi-autonomous planning body was set up 10 years ago by the architect Mario Coyula. His small team - a core of just nine people - occupies a purpose-built building, at the heart of which is the makings of the world's finest city model. The only comparable study model can be found in New York and it is not as convincing. No British city, not even London, has a model to compare with this.

The model being built on a scale of 1:1000 will eventually measure 22m by 10m. It will be used to explain past, present and future developments in Havana to schoolchildren, the public, politicians, developers and architects. Mounted on 36 2m by 2m table tops (representing 4sq km of the city centre), the model will move on rails driven by electric motors so that those who explain it (and maintain it) can work their way through the city.

Progress on the model is slow, because a lack of welding rods and power makes it tricky for builders to finish the building it is to be housed in. The model-makers themselves have to work patiently with what few materials they can obtain. They make their own tools (including knife blades), their own glue and construct extremely accurate miniature buildings (even the wings of the angels on the heroic tombs of the city's famous Columbus Cemetery are reproduced) from the cedar wood of empty cigar boxes. In Havana, no scrap of material is wasted.

The tiny buildings are painted three colours, representing the three major phases of the city's development. These are the colonial era (1519-1898), the post- Independence era of rapid growth, technological development and American- style streets, avenues and architecture (1898-1959) and the Revolutionary years (1959 to the present).

The effectiveness of the model - even in its incomplete state - has already been proved. Miguel Coyula (another member of the team), enjoys telling how, after a seven-year fight, a Canary Wharf Tower lookalike planned for a site beside the Plaza de la Revolucion was refused planning permission after the city's political leaders saw the effect this ugly building would have on the Havana skyline. A miniature of the tower was added to the model. 'The meeting', says Mr Coyula, 'could not have lasted more than 10 minutes'.

The model of Havana is also linked to a sophisticated computer programme, 'City Manager', being developed by group member Ricardo Fernandez, together with the Faculty of Mathematics and Cybernetics at Havana University. Mr Fernandez has been working on the software for three years. Almost complete, it gives instant, detailed information on any individual building in central Havana. For example, it can direct firemen to hydrants and tell them what is housed in buildings beside those on fire (hazardous materials, children, stores of paper etc).

New building projects can be shown in three dimensions so that their effect on the city skyline can be judged. 'City Manager' is probably the most detailed and effective computer software of its type. When complete it will be in demand by city planning offices as well as by architects, developers and emergency services worldwide.

Mario Coyula's group is also involved in projects to turn solid waste into methane gas to power the shanty town slums it is encouraging local people to rebuild in the poorest parts of Havana. It has developed a method of transforming rubble into cheap and strong building materials to repair houses and it runs urban workshops in various parts of Havana to show citizens how they can help themselves.

The architects fear that Havana - Old Havana aside - will be transformed one day into a semblance of Miami, that it will lose its special character and architecture (rebuilding Havana is a task that even Hercules would find daunting) and become prey to ruthless foreign development. Their ideas for architectural and urban self- sufficiency should be learnt in Havana and by the rest of the world, before all our major cities go the same way.