Purist geometry and a sophisticated structure elevate this apparently modest project for a Swiss school into an expressive contemporary homage to Neo-Rationalism
The first reaction to this small schoolhouse in a small village, the first completed building by Swiss architect Raphael Zuber, is surely bewilderment. And though the harder you look the more you understand, it does not diminish the sense of astonishment at so much architecture in such a modest building.
Grono is an unremarkable village of 900 inhabitants in a valley at the southernmost tip of Switzerland’s largest canton, Graubünden, bordering the Italian-speaking canton of Ticino and Italy itself. In common with many Alpine valleys it is less than bucolic, part of a densely filled north-south transit way of roads, railways, light industrial buildings and suburban sprawl. As is common for public buildings in Switzerland, the village staged an architectural competition to replace its hundred-year-old schoolhouse. Zuber won it in 2007.
The site plan is emphatic in its assertion of the building as an object: it is a square within a circle in the middle of its site. But as is the rule with this building, its purity is regularly subverted. The building is actually two schools: a kindergarten and a primary school.
The necessary separation between the age groups is achieved almost unnoticeably with separate entrances and external spaces. Older children enter over a bridge on the north side, from which the building appears to have two storeys, directly on to the first floor.
The kindergarten is entered on the south side on the ground floor, which, because of the slope, opens out to a depression circumscribed by the low, circular wall of the play area. The slope also naturally makes each facade different although they are in fact identical pairs. The middle storey, containing the assembly hall and other more public functions, is appropriately taller in section than the other floors. A graceful, semi-circular stair transforms the central space on each floor into much more than just a corridor.
Although modest in programme, size and budget, the building is highly sophisticated, oscillating between autonomous and contextual, floating and solid. The importance of a school building to a small, remote community is clear in its siting in the centre of Grono on what was the village green. With its huge arches, the concrete exoskeleton confuses your sense of scale, giving the building a monumental character that at first surprises, but on reflection seems apt. This monumentality is contradicted, however, by the formal treatment of the walls, which dissipate towards the corners and indeed float. The large circular cut-outs further enhance this sense of weightlessness.
When combined with the formal language of simple geometries, the separation of structure and programme is an obvious nod to Italian Neo-Rationalism, but also more profoundly to Louis Kahn’s idea of served and servant spaces. Indeed, a generation of Tendenza architects – Luigi Snozzi, Aurelio Galfetti, Flora Ruchat, Livio Vacchini and a young Mario Botta – were explicitly influenced by Kahn.
In contrast to the monumentality and symmetry of the exterior, the plan is not at all rigid but rather accommodates circumstances pragmatically. The programme defines the spaces and the plan responds as it must. The bridge pushes in and creates an entrance; the stair creates a kink in the classroom wall on the floor above. Views from individual rooms through the perimeter expanse of glass are always mediated by the external walls. The two systems of glass and concrete slide past one another, so the view changes depending not only on what room you are in, but also where in the room you are. The sense of enclosure, of being inside or outside, is highly variable.
This interest in heavy yet light, autonomous yet contextual, transparent yet occluded, continues with the treatment of the exterior concrete. Integral pigmentation makes it overtly decorative and a clear rejection of a truth-of-materials position and the ubiquitous Swiss béton brut. On the other hand it is also naturalistic and reinforces the image of a plant, with the actual colour chosen to match the local soil. What’s more, this valley is unusual in that the tree cover is not fir but deciduous chestnut and walnut, so the building blends in to its natural landscape.
Even though this is a relatively modest building in a small village, the architect worked with a prominent engineering firm, Conzett Bronzini Gartmann, which has collaborated with many leading Swiss architects (AR February 2007). Not unusually for Switzerland, the engineers are still based in their hometown (in this case the cantonal capital Chur, where Zuber also has his office) and still maintain an interest in smaller projects. As with the architecture, the engineering strategy is startling in its geometric simplicity and clarity; in this case, no more than the rectangle of the lift core, the arc of the stair and the two pairs of pillars supporting the arches.
Through layers of timber, concrete and glass, the classrooms look out on to the verdant valley landscapebeyond
The central lift core and rounded wall of the stair take most of the vertical load of the floor slabs, and corners are opened up to maximise daylight by post-tensioning the outer edge of the slab. The elliptical form of the facade is efficient statically. (A parabola would have been even more efficient but difficult to construct.) All structural elements, including those inside, are concrete. All other walls are either block or glazed. Large openings in the facade reduce the weight of the walls and allow yet more daylight in.
Though this may be a modest building by a young architect, it is anything but modest architecturally. Driven by not style but by a series of decisions rooted in addressing architectural problems, it shows a passion for the means of architecture and the richness inherent in it.