Suburban bibliophile.

The following critiques focus on buildings that reflect more mainstream programmes, tempered by architectural and social concerns. We begin with an appraisal of a new library and council offices for the Johannesburg suburb of Sandton.

Sandton is a northern enclave of Johannesburg, a bastion of white bourgeois lifestyle that placidly revolves around shopping malls, office parks and fortified villas. Unlike the bustling inner-city core, it has a suspiciously sanitised, dislocated feel like that of an American suburb - and is similarly in thrall to the automobile. In an attempt to redress its shortcomings as a civic focus, the centre of Sandton (paradoxically known as Sandton City) is in the process of being heroically recast as a kind of cinquecento plaza, colonised by great slabs of stage set Neo-Classicism. With its mixture of shops, offices and restaurants it is an unquestionably bold attempt to implant some sense of place (albeit sixteenth-century Verona), but Developer's Italianate sits uneasily alongside the rest of Sandton's undistinguished commercial sprawl. One aspect of this civic vision that has fared rather better in its physical realisation is a new public library and facilities for Sandton Town Council (currently housed in an adjacent featureless slab block). These functions have been combined in one building, which has the difficult task of squaring up to the encroaching Brobdingnagian assemblage.

The new building both defines and is defined by its surroundings yet in an intelligently ad-hoc way. It occupies a pivotal, wedge-shaped site between the new commercial square to the west and a more formal public open space to the east. With its facades defining one side of both squares, it becomes a major element in each composition. The building evolved as three wings organised around a triangular courtyard. The courtyard is glazed over to create an immense light-filled well in the heart of the building, which symbolically links the two public squares. To progess from one to the other, there is a choice of routes - the internal route through the library or an external walkway along the south side of the building. The walkway with its fiendishly and fashionably cranked canopy demarcates a further tier in the hierarchy of public space - a contemplative sculpture garden that forms part of a small local art gallery.

In plan, the building reads simply - enough the east and west wings contain library stacks while the slightly curving south segment houses support facilities. In section, however, it is more complex as the one-storey difference between the surrounding external squares is resolved by an ingenious helical floor arrangement, consisting of six half levels. Far from being a passive void, the library's central court becomes the focus of circulation, through a suspended trolley ramp that snakes vertiginously around the edges of the atrium, weaving the various half levels together. There are lifts enclosed in a sculptural cylinder for the fainter hearted. The smaller floor plates resulting from this arrangement enable individual departments within the library to expand and contract more easily.

The topmost level is a conventional floor housing the executive of the local council. The offices have views into the court below, so the body politic is under constant surveillance by its electorate. There is also a semi-circular debating chamber - though with local government through South Africa in a state of post election flux, the future of Sandton's council must be considered uncertain.

The east-west orientation of the site, coupled with the need for large areas of glazing on the library floors gives rise to deep set backs that are strongly expressed in the elevations. The massive, muscular, raw brick facades are articulated by metal balconies and the crisp Euclidean geometry of window openings punched deep into the walls. The combination of unadorned brick and metal is a clinical antidote to Sandton's hysterical stylistic confusion. The platonic formality of the composition is invariably reminiscent of Kahn - the flat arches in particular are pure Exeter Library. (Kahn's influence on a generation of South African architects, including GAPP's Glen Gallagher, cannot be underestimated.) On the west elevation facing the commercial square, a monumentally overscaled triangular opening marks the office of the council's chief executive.

At an altitude of 6000ft, Sandton's highveld climate is dry and hot, with conditions particularly intense during the summer months. Apart from the set backs, climate modification takes the form of retractable fabric sunscreens in raw primary colours which are automatically controlled by a solar cell, linked to the sun angle.

On paper, the hybridisation of public library and council offices seems contradictory and unpromising, yet at Sandton the hierarchy of scale generated by different functions imbues the building with an appropriate civic grandeur. By contrast, the library areas are intimate and welcoming - especially important to those seeking knowledge or studying for the first time. The heavy, imposing facade conceals a delicately transparent heart. For all its hard urban posturing, Sandton's new library has a soft centre.