Towards a new MoMa.

Since its founding in 1929, New York's Museum of Modern Art has evolved from an obscure institution with a staff of four located in 4000 sq ft of rented space in Fifth Avenue, to an international super-museum with a staff of 500 and a collection of almost 100 000 objects occupying 325 000 sq ft. Throughout its 68 year history, MoMA has been expanding incrementally on its West 53rd Street site. In 1939, Philip L. Goodwin and Edward Durrell Stone's progressive International Style building replaced the original Beaux-Arts townhouse, providing space for the Museum's burgeoning collection and facilities such as an auditorium, film centre, library and open-air sculpture space. Together, these established MoMA's distinct character based on a diverse and challenging cultural remit.

However, since the Museum was established, lack of space has always been an issue. This has been addressed by a succession of additions (by Philip Johnson during the '50s and '60s) and a more recent remodelling by Cesar Pelli in 1984. Yet the ability to achieve a new configuration has historically been limited by the Museum's mid-town, mid-block site. Until now, opportunities for expansion have entailed growing to the east and west along 53rd Street, creating a narrow, linear configuration of galleries that may be appropriate for a narrow, linear chronology of modern art, but failed to fulfil MoMA's loftier goal of disseminating the broader meanings and diversity of modern art. The problem has been further exacerbated by the structural and mechanical requirements of the residential tower built above Pelli's 1984 extension. By the early '90s the Museum was considering strategies for further expansion, including the radical option of moving all or part of the collection to a new location. Concluding that it was vital to maintain its presence on 53rd Street, but equally essential to alter the narrow footprint of the current building, in 1995 the Museum seized the opportunity to purchase the Dorset Hotel on West 54th Street and two adjacent brown-stone townhouses. For the first time in its history, MoMA's galleries now have the potential to extend the full width of the mid-town block, allowing the creation of a more diverse series of spaces that can more fully accommodate and represent the Museum's collection.

The first stage of this latest expansion phase has involved inviting 10 selected architects to participate in a charrette, or problem-solving design exercise. The aim of the charrette was to produce a variety of proposals for discussion, that explored basic conceptual strategies for the redevelopment of the entire museum. As a means of deliberately discouraging elaborate presentations, submissions had to fit into a box measuring 11 x 17in, issued to all the participants. Three shortlisted finalists (Herzog and De Meuron, Bernard Tschumi and Yoshio Taniguchi) have been selected to develop their proposals further. Other participants included Dominique Perrault, Toyo Ito, Rem Koolhaas, Wiel Arets, Steven Holl, Rafael Vinoly and Tod Williams and Billie Tsien. All 10 schemes were on view at a recent MoMA exhibition entitled 'Towards a New Museum of Modern Art: Sketchbooks by Ten Architects'.

The Museum has hitherto evolved along an east-west axis, giving rise to an elongated form focused around Philip Johnson's sculpture garden. Lying to the north-west of the existing museum, the new site fundamentally alters the balance of usable space, and its integration with the old MoMA presents many challenges. The obvious temptation, to split the site down the middle on the existing east-west axis, was followed by several competitors, including Taniguchi. However, this creates north and south sections separated by canyon-like spaces that generally fail to integrate with the new Dorset block. Williams and Tsien's proposal of circulation knuckle in the south-west corner of the sculpture garden was one of the more inventive solutions to this problem.

As the focus of the existing museum, the sculpture garden will require sensitive handling, and most schemes either retained or enlarged it. Tschumi, for example, extends it into his new building, as a means of drawing in visitors, but Herzog and De Meuron regard it as potentially dispensable, exiled to a roof and replaced By a new entrance court. Another factor is the essentially intimate character of MoMA's galleries, which may not survive the escalation in scale. Some, such as Koolhaas and Perrault acknowledged this and opted for large, self-regarding interventions; Perrault proposed an elevated bridge to a top-floor gallery/plateau and Koolhaas (perhaps inspired by the Centre Pompidou's much celebrated ceremonial escalators), a cable car running diagonally through stacked cubes of galleries.

Throughout its history, MoMA has used architecture as a vehicle of self-renewal and regeneration and this latest exercise promises to be no exception. Having survived the charrette, Taniguchi, Tschumi and Herzog and De Meuron are now set to develop their proposals further by the end of the year.