BALLYMUN is the classic example of high rise, low density housing. A legacy of Le Corbusier's warped, city killing vision of the Ville Radiuse tower blocks laid out in open parkland, criss crossed by "distributor roads" - it is an aberration, like all the other vast, system built housing projects which litter the outskirts of cities internationally.

Ballymun was barely finished in 1969 when the authorities decided to try out its obverse - low rise, high density housing - in Darndale. "Out goes the Ballymun idea and in comes the new brainwave for suburban living," said the Irish Builder. "It will be a haven for children ... Each family will have its own playspace for tiny tots".

Designed by Lardner and Partners, Darndale was to have 3,000 houses laid out around small courtyards and alleyways, with "all amenities" including two shopping centres. The concept was borrowed from Andover, in England, but its designers crucially failed to take into account that Irish working class families tended to have more children.

Darndale turned out to be a housing disaster, just like Ballymun. Instead of creating a sense of intimacy and belonging, the high density nature of the scheme - and the number of children per house - merely made it claustrophobic. And since none of the promised "amenities" materialised, it wasn't long before Darndale also became a ghetto.

The early 1970s marked the nadir of modern architecture and town planning. "Prefab ghettos next", moaned Plan magazine, in an editorial on the "low cost housing" concept adopted by the National Building Agency and the Department of Local Government.

The pre fabricated, usually flat roofed, houses didn't even last 20 years before most of them had to be encased in new walls and pitched roofs. Meantime, Dublin Corporation reverted to more traditional housing, creating huge, low density estates on the city's periphery.

From the early 1980s onwards, the Corporation also built hundreds of housing units in the inner city. Two and three storeys high, reflecting an obsession with giving every tenant a front door onto the street, these schemes could be regarded as a gross waste of expensive urban land and, in terms of scale, represented a suburban invasion.

More recent models, such as Bride Street and Marrowbone Lane, with their cleverly designed combination of houses and flats, are more appropriate to the inner city. However, looking back over the past 30 years, what we have witnessed is a series of ad hoc exercises in social engineering, with local authority tenants as the unwitting guinea pigs.