Sculptural stadium.

The architects aimed to make a building that 'reverberates with its surroundings' while enriching the experience of Parisian sports enthusiasts.

Any self-respecting stadium project nowadays sports politically correct pretensions to urban integration or environmental dialogue. Yet how many such would-be coliseums - heavily promoted and packaged as the locomotive for urban regeneration, turn out to be anything more. than introverted fortresses, stranded in an ocean of car-parking and swathed in the paraphernalia of security and sponsorship? Precious few.

The Charlety stadium, completed last year to designs by the father-and-son partnership of Henri and Bruno Gaudin and located in the thirteenth arrondissement of Paris, is an exception. It replaces sports facilities designed for the 'Paris Universite Club' (PUC) by a team of architects led by Bernard Zehrfuss and opened in 1938. Neither the 1000-seat stadium nor the ancillary accommodation met current needs.

The PUC ground forms part of the Cite Universitaire, a linear campus developed from the 1920s - one of the few sectors of the redundant 1840s Paris fortifications to be redeveloped on garden city principles (elsewhere, a dense band of housing, bounded by a narrow 'green belt' is largely given over to sports grounds and cemeteries). Always separated from the city by the Boulevard des Marechaux ring road, the Cite Universitaire and the PUC sports ground has, moreover, been cut off from the suburbs by the peripherique motorway box since the 1960s.

As the PUC lacked the means to rebuild and modernise its sports facilities, the City of Paris finally stepped in and launched a competition for the 8.5-hectare site in 1988. The brief called for a new, fully equipped stadium with an all-seated spectator capacity of 20 000, offices for the French Olympic committee, club premises and further sports facilities for the PUC, including a 1400-seat multi-sport indoor arena, an outdoor training ground, running tracks, tennis courts and 1500 underground car-parking spaces. Planned for use by the City of Paris as well as the university club, the future stadium was never intended to be in the Olympic or World Cup league. To offset costs, 10 000 sq m leasehold office space was required. Also included in the brief was 25 000 sq m housing (later omitted in favour of a public garden). Henri Gaudin saw this programme, 'not simply as a stadium but an entire urban block, in which the stadium should reverberate with its surroundings' - an ambitious objective, given the realities of the urban context.

The Charlety site is jammed between the peripherique, the Boulevard Kellerman (the name of this section of the Boulevard des Marechaux), and the Avenue de la Porte de Gentilly - across which it is overlooked by Le Corbusier and Lucio da Costa's 1957 Brazilian student pavilion. To the east, the site is bounded by a cemetery, with 1930s housing blocks beyond. To exploit the slightly trapezoidal site in plan and to establish direct contact with the Parisian urban fabric while providing an element of continuity with the Cite Universitaire's southern stretch of park, the Gaudins have planned their stadium as an ellipse, with its north end meeting the Boulevard at a slight tangent.

Moored to the stadium by the PUC's club premises and multi-sports hall, a ship-like range of offices along the Avenue Gentilly has a glazed prow, marking the main public entrance to the stadium at the junction between Boulevard and Avenue. The stadium forecourt, which is reached directly from the pavement, is dynamically funnelled between the opposed curves of prow and ellipse. This sweeping spatial momentum is emphasised by flights of steps giving access to the stadium, which wrap around the raking-shore buttresses of the grandstand.

Within the new stadium, two tiers of seating define its elliptical configuration. To provide extra rows of seating on the long sides (preferred by spectators), the upper tier is swept higher and, on the west, is oversailed by the grandstand. With the exception of the Teflon sails suspended from lighting masts to give lateral protection to the grandstand, the structural framework for the stadium as a whole is provided by highly articulated raked concrete buttress piers. Cantilevered off these concrete piers, in a dynamically organic deduction of compression and tension that acknowledges French Rationalist traditions, is the undulating steel canopy. A dramatic interval of sky is created between its swooping, dipping roofline and the topmost row of seats.

The Gaudins have opened up direct visual links between stadium and city by omitting four entire bays of the upper seating tier at the narrow ends of the ellipse. Here, the vertical structure becomes a portico which, at the northern end, gives directly onto the Boulevard pavement. 'It is a colonnade offered to the city at ground level, a gallery that distributes and clearly defines the stadium,' as Bruno Gaudin puts it, 'being on the same level as the city, and in continuity with it, is of primary importance'.

Permeability, and the interplay of internal and external space, are recurring themes in the Gaudins' work (AR March 1994, pp31-37). At the Charlety stadium, they have contrived to create a building that enriches the experience of sports spectators while at the same time enhancing the city.