Concrete Finns.

Precast concrete housing gained an often deserved reputation for shoddiness in the 1960s. This scheme shows how modern prefabrication techniques can achieve the qualities that were only dreamed of 30 years ago.

Ruoholahti is part of the western harbour of Helsinki, not a long walk from the elegant centre. Up to now, it has been rather run down, with decaying industrial buildings and nineteenth-century tenements next door to the still thriving shipyards in which huge Baltic ferries (which seem to be the size and height of a city block) always appear to be undergoing mysterious, very sparky naval operations to make them even bigger and more luxurious. The city authorities have produced a plan for the district which is intended to give the area the mixed uses of a proper urban area, and of course it must incorporate a large residential element. One of the first results is the Laivapoika scheme by Pekka Helin of Helin & Siitonen.

The planners demanded an urban block that could take its place as one of the key and defining elements of the reconstructed quarter. And at the same time, both they and the funding system demanded a very complex interweave of habitation types and functions: all new housing schemes in the area must contain free-market owner-occupied flats, government subsidised owner-occupied flats and social housing for rent. A very wide range of people had to be accommodated, ranging from large families to individuals and elderly folk; a group dwelling for the disabled was required, as were individual flats for elderly and ambient disabled. The larger flats are subdivisible so that they can change as families alter in structure. All flats had to have a spacious balcony or roof terrace. Some of the larger ones have a sauna, and there is a communal sauna on the roof with a terrace overlooking city and sea. Other communal rooms are provided at ground floor.

This very complex and necessarily dense programme has been arranged round a central court, taking its pattern from the six-storey walk-up block that dominated nineteenth-century northern European urban cities from Edinburgh to Berlin, Oslo to Paris. The pattern may be old, but the complexity of the programme (and the funding system) necessitated use of a virtually standard precast concrete system: the sort of construction that made much Finnish housing so drear in the '60s and '70s. The Ruoholahti scheme has managed to overcome limitations of cost and manufacture with remarkable ingenuity, and it has broken open the traditionally contained nineteenth-century block to offer a delicately nuanced sequence of external spaces ranging from public promenade, to semi-private (the open-ended court) to intimate (terraces and balconies).

The site is wedge-shaped, with its east apex on an uneasy corner of busy roads. To the north is an elegant new canal and urban landscape by Juhani Pallasmaa which terminates in a circular basin, intended to act as a landmark and centre for reconstructed Ruoholahti. Southwards, the Helin & Siitonen scheme looks out over the road to the harbour. West, the parti opens itself to the afternoon sun.

The complex falls into three main pieces, two six stories high, with a north-east corner tower a couple of floors taller. The parts are linked by flying balconies which, constructed of steel and enclosed in glass blocks, provide delicate knitted seams between the heavy concrete walls of the enclosed dwellings. The balcony tower at the eastern apex of the court is intended to act as a prism, collecting and reflecting light into the public space.

I can't say whether or not this works, for when I visited the place, the sky was overcast. Yet even on a dull day, the quality of control over the standardised construction system was very clear. The precast panels are either white-smooth, or blue-grey, the latter deeply, precisely and finely grooved, giving a surprising delicate and sensuous quality to the places which you can touch. The quality is perhaps finer than can be found anywhere in most other such routine work because the Finns have never given up using precast concrete for making housing, and have put enormous amounts of thought and money into improving techniques of its manufacture. The heavy concrete elements contrast with dark blue shiny pressed steel vertical elements, which cover internal services towers - and evoke the huge nautical metal bending works down the road. Near entrances, matt-finished sheets of gabbro add an honorific note - and an easily cleaned one.

Natural materials and detailed craftsmanship are emphasised in the landscaping of the court to contrast with the industrial nature of the buildings, for as Helin says 'industrial construction requires the additional touch of the human hand'. Planting is with native sub-boreal vegetation: crab-apple, wild rose, juniper, yew, dwarf pine in the court, with maple and ash on the canal bank.

The plants will thrive and make a compact between urbanity and nature, just as the architects have made a most elegant and inspiring series of relationships between standardised industrial production of space in volume and the needs of particular families and individuals.

The design was made at the bottom of a very deep slump into which the Finns fell as a result of being the link between the Western and Soviet economies when the USSR collapsed. Its bravery and decency were justified. The Finnish economy has recovered now, and is one of the most successful in Europe, Ruoholahti shows how generous social vision, an inventive understanding of how to use technology for human ends - and optimism - can be invested to make the world a better place to live in.