Cool urbanity: metal is the main material that allows this centre to help make a Finnish suburb into a real piece of civic design, and focus for a disparate community.

The suburbs of Helsinki, as of many other northern European cities, often show the least cheering aspects of Modernist planning, with individual buildings and blocks scattered into a vacuous waste of roads and meaningless unusable green. Socially, the fabric is often as fragmented as the physical one, with immigrants from rural areas or from abroad mixed hugger-mugger with some of the least privileged traditional citizens. Recently, there has been a programme for building a network of suburban cultural centres round the Finnish capital to try to create more focused communities. The Vuotalo centre attempts to knit the community of an eastern Helsinki suburb physically as well as socially. Heikkinen & Komonen's work has long been characterized by bold and apparently arbitrary geometric moves which, on close inspection, turn out to be subtle and humanly rewarding.

At Vuotalo, the parti is based on an 80m diameter circle which relates the major elements of the surroundings, the Vuosaari High School to the east; south, a big shopping centre which bridges over the motorway, and to the north housing and an as yet unbuilt elderly persons' day centre. The axis of the shopping centre cuts the circle in half. To the west is the building, to the east is a new civic piazza, or rather two piazzas, one carved out of the open half of the circle to reflect the axis of the school, and sunk 3m. This wedge is planted with whitebeam, and should eventually be almost as magical as the sunken citrus groves of Marrakech.

The upper wedge of the piazza is paved, and forms a forecourt to the building itself that rises two storeys above ground and is clad on its piazza side by a continuous clear curtain wall. Here, the footpath that runs between the housing to the north and the shopping centre (and crosses over the lower piazza wedge on a bridge) is paralleled inside by a double-height continuous glazed foyer. Over the path are slender steel arches designed to carry banners that give a festive and heraldic flavour to both internal and external paths. Light fittings are suspended from wires.

Internal planning is very straightforward, but made spatially and formally rich by the clash of grids between the east-west orientation of the school and the diagonal slash of the foyer. The large southern part of the ground floor is a public library, with a northern wedge containing the auditorium. Above on the first floor is a complex of small rooms: art studios, music practice spaces and the like. The levels are related by bold moves. Two wide trenches in plan allow skylight to be brought into the middle of the deep plan (a continuing Finnish preoccupation this). The other big move is the spiral stair that winds from the foyer to the upper floor (and down to car park level).

The west (curved) side of the building is completely different. While piazza and foyer are visually united through the glass wall, the back of the building - clad in a woven stainless-steel product that is normally used in industrial conveyor belts - is impassive during the day, with the taut steel mesh glittering in sunshine or calmly grey in winter. At night, the mesh becomes almost transparent, with those parts of the interior (unlike the auditorium) that can be open radiating light outwards through the metal fabric and giving an abstracted image of the inner life of the cultural centre. The impassivity is a response to the busy bus road to the west of the site, and mesh and its light-modifying properties is one of the continuing fascinations of the practice (see for instance AR March 1990 and AR August 1998).

The treads of the spiral are in birch: a moment of relaxation from the otherwise rigorous foyer discipline of sealed concrete floor with glass and steel walls. Pale wood is used again to make the reading spaces of the library welcoming and easy places to study in, with top light flooding over latticed timber walls that conceal the small rooms on the upper floor, and relate them to the reading rooms below. Here are floors of heat-treated birch (a process which hardens and darkens the wood). Stacks are under the studios on the first floor, providing book-lined caves on each side of the luminous main adult reading room. Through the glass walls of both libraries are views of the new landscape - at the moment, until it grows to mask the bus road, vistas are mercifully muted by the stainless-steel mesh.

Vuotalo is simultaneously open and closed, functional and heraldic, tough and rigorous yet gentle to individual users. It is a civic hub in what was previously a disjunct part of the city. And it was produced to a remarkably small budget.