Geometry lessons.

Lying at the foot of the Sierra Grande, to the north-west of Buenos Aires, Cordoba is Argentina's second city. Originally an important colonial stronghold and Jesuit centre of learning, Cordoba is now a sprawling, industrial metropolis. From a traditional Hispanic grid, the city radiates out across the fiat foothill plains, gradually fragmenting into featureless suburbia. To give these peripheral neighbourhoods a greater sense of place and civic cohesion, the municipality has been engaged in a programme of decentralization, moving various government and university departments out to the suburbs. As part of this strategy, local architect Miguel Roca has been involved in building a series of small community centres on edge-of-town sites. To date, nine of these Communal Participation Centres (CPC) have been completed, and on the following pages we look at two of the most recent ones.

The centres are intended to give a social and civic focus to particular neighbourhoods, but they also deal with a range of administrative and municipal functions such as public and private works, tax and finances, civil registry and social services. The programme draws on Roca's experience of designing a similar series of community buildings in the Bolivian capital of La Paz (AR October 1992), which required a strong physical identity in often chaotic urban surroundings. Here, as with La Paz, Roca employs interlocking geometric volumes to convey a sense of modest, municipal monumentality. A common language of scale, forms and materials also helps to establish a generic typology, so that each centre reads as an individual building, but is also identifiable as part of a more general civic initiative.

CPC MONSENOR PABLO CABRERA

Located on the busy main road to Cordoba airport, this centre also acts as a symbolic entrance portal to the city. From a distance, the building appears as a massive, squat cylinder, its top sharply sliced off at an angle. Closer inspection, however, reveals the external wall to be a permeable screen wrapped protectively around the various volumes that make up the centre. In some ways, the entire complex resembles a small hamlet or semi-fortified outpost, its various functions expressed and articulated by Roca's solid geometry and yoked together by the curvaceous embrace of the perimeter wall.

The focus of the composition and main organizational element is a wedge-shaped internal street. This is connected to a cylindrical theatre and a smaller cube and cone housing the local mayor's office and municipal meeting hall respectively. External spaces between the main volumes and enclosing perimeter wall are transformed into secluded internal gardens by an austerely simple landscape of pebbles and bamboo plants. On the road side, an elevated walkway traverses the highway and docks into the curved flank of the building. This bridge also forms a gateway marking the outskirts of Cordoba.

Rising up through the building is a three-storey internal street and circulation spine. Along each side of the street are strips of cellular offices and workshops, given over to various municipal activities. Generously scaled, the street has an informal, forum-like quality, designed to encourage casual exploration; the aim, after all, is to make local people aware of the range and nature of the building's services. A huge flight of stairs cascades down through the street and rows of sawtooth rooflights bring light deep into the cavernous space. Materials are deliberately robust and low-maintenance - brick, painted concrete and stone - yet there is an uplifting sense of decency and dignity coaxed from evident economy of means.

CPC ROUTE 20

This new Community Participation Centre on Route 20 also acts as an urban gateway, this time on the western approach to Cordoba. The centre is divided into two parts: a cylindrical block houses municipal and administrative facilities and a roughly lens-shaped volume contains social and cultural spaces. Between the two buildings, Roca has created a new public square.

The administration cylinder is based on a simple parti of cellular spaces arranged around a glazed circular court. Here too, bold geometric forms are used to articulate particular functions; the mayor's office is housed in a composite cube and cylinder and the local meeting hall in a cone. These volumes are pulled out from the main cylinder to frame the entrance. With its sweeping stairs and galleries, the circular court forms the dramatic, luminous heart of the building, animated by the bustle of staff and visitors. Again, the arrangement of volumes helps to generate a sense of permeability and openness. Light is filtered through a rooftop sunscreen, which also acts as a solar collector.

The cultural centre is a more complex organism. A lens-shaped hall links a quartet of volumes, each allotted a different cultural or social function. The hall becomes an internal street, with a barrel-vaulted multi-purpose space and small theatre at each end; in between are a library and cafe, with classrooms above. Here the geometry is less regular; the spaces are cranked casually into the street, creating intimate enclaves and emphasizing the building's informal, social character. A sensuous, wave-like roof unifies the entire composition. Generating a humane civic presence in a featureless public realm is a delicate balancing act, but Roca's synthesis of strong, legible forms, simple materials and inventive placemaking confounds such contradictions.