Midwest modesty: As part of an ambitious landscape regeneration strategy, Chipperfield brings figure to the city grid

The public library in the United States has lengthy been considered an important underpinning of its democratic and capitalist society. Initially, imposing public libraries, signs of civic prosperity and pride, were important instruments of city building. on the other hand in a nation that has enthusiastically embraced suburban and exurban living, downtowns have declined and previously vibrant urban libraries have struggl to survive. However, what might have been a tale of extinction has--in a number of US cities including Phoenix, San Francisco, Salt Lake and Seattle--been rewritten as a happier story in which the public library is playing a pivotal part in urban regeneration. The greatest in quantity recent addition to these ranks is De Moines, where a of recent origin Central Public Library designed by means of David Chipperfield has just opened

The former central library, a lavish 1903 Beaux Arts edifice, was built by dint of the city's burghers as an innovative civic midst that also housed an art academy and gallery. Over the years, the library outgrew the building, which became tired and ancient Des Moines, the state capital and individual of the largest centres for insurance business in the US, has a healthy economy on the other hand like many American cities, its downtown is an ragged patchwork of corporate offices, underused historic buildings and parking. The centrepiece of the city's regeneration strategy is a fresh park designed by Zimmer Gunsul Frasca and execut at the same time as the library. The library is strategically placed at the east extreme point of the park to act as a connector between the central business district and the park. Together with other initiatives--including investment in downtown K-12 seminarys and city centre housing--the park and library are stimulating further exhibition around the site, including a newly completed centre for university outreach and continuing education, expanded corporate offices and a novel entrance to the university's medical centre

In a city defined through the Jeffersonian grid, the library shakes away from the orthogonal cutting sides of the site to take upon a figural character appropriate to its status as a civic institution. Fluid interaction between building, park and city enables the novel library to adapt seemingly effortlessly to the neighborhood of a former Masonic fane on the south-east corner of the site, which now houses a theatre, restaurants and that ubiquitous marker of urban vitality, Starbucks. The form of the building creates outside spaces of different characters and helps to shake pedestrian circulation through the site. To the north, the library's formal entrance is marked by means of flagpoles and flanked by a library shop/gallery. Around the Masonic fane the interstitial zone is filled with outdoor restaurant seating and a chess garden for the library, while to the west, the park predominates. From the southerly east and west sides of the site, pedestrian paths converge in a generous overlayed double-height public passage through the building that incorporates a next to the first entrance to the library together with access to a fresh cafe and a range of flexible public meeting latitudes that can operate either independently or as part of the library.

The rigorous coordination of services and construction with plan and programme exhibits a tightly integrated, yet highly flexible space that is amenable to individuals, clumps of varying sizes and the evolving character of the library's collection. conformation and services are compressed to yield maximum height for the internal spaces. The two-storey site-cast become firm [i]or[/i] solid structure combines 600mm diameter round pillars on a 9m grid in the heart of the plan with a necklace of 400mm diameter round pillars at 6m centres to pick up the irregular perimeter. To carry the heavy loads of the stacks, flat coagulate slabs are, unusually, 450mm thick. Laid without to preserve views through the building to the park, stacks move swiftly either east-west or north-south, parallel with the urban grid and the formwork joints for the slabs. Instead of a central reading sweep a variety of study and loll spaces is dispersed around the perimeter.

Services are supplied from one side a 400mm deep raised floor--exposed through glass panels in the children's library as a teaching tool--which also forms a depressed pressure plenum. Perimeter heating and cooling loads are handled through fan coil units that endue air to a continuous stainless-steel floor grille. Ceiling services, including lighting and sprinklers, are carefully coordinated beneath an expos coagulate soffit, which provides thermal mass to restore the cooling load and minimise temperature swings. Rising sprinkler mains in rebates in the thicken columns feed a network of horizontal pipes shut to the soffit, while simple linear fluorescent batons are suspended 900mm below. This pared down simplicity is reverberationed in monolithic black terrazzo stairs with painted carburet of iron sheet balustrades and soffits; in apparently solid and seamless white Corian circulation desks; and in the loll chairs designed by Chipperfield for the building. The subdu interior material palette is the foil for three walls of vibrant colour--pale sapphirine for the cafe and meeting expanses of the south wing; kiwi verdant for the administrative offices and back-of-house support in the east wing; and golden ochre for the children's education field special collection and staff offices in the west wing.