Primary school library by Kéré Architects
This building in rural Burkina Faso makes innovative use of clay pots in its ceiling to aid lighting and ventilation
Location: Gando, Burkina Faso
Architect: Kéré Architecture
Construction: Community of Gando
Completion date: January 2012
Clay pots normally used for storing food have been used to form openings in a concrete ceiling to provide indirect light and ventilation to a new school library. The amount of sunlight entering the building needs to be restricted, since the new building is in Gando, a small and remote village in Burkina Faso, west Africa, where temperatures can exceed 40°C.
The effect on the interior is to cast different-sized circles of light on the floor, creating random patterns.
The idea of using a locally made product to help the building function better came from Francis Kéré, director of Berlin practice Kéré Architecture. The library is the latest in a series of buildings in Gando designed by his practice.
Kéré was born in Gando and as the first child of the village’s chief has the respect of the community. Kéré Architecture has designed and built a primary school, teachers’ accommodation and a school extension in the village.
Kéré’s buildings employ principles of climate comfort and low-cost construction by using local materials and making use of the local community to build them.
The £43,000 single-storey library comprises 300mm-thick traditional load-bearing walls made from stabilised and compressed adobe blocks laid on a concrete foundation.
An overhanging metal roof supported by steel trusses is positioned over the concrete ceiling to provide shelter and to enlarge the space that encircles the library. Elliptical areas dug out of the earth provide seating.
On the long elevations, thin trunks of eucalyptus are spaced along the facades to provide a sunscreen and a sheltered space.
Roof structure and concrete ceiling
The library’s concrete ceiling will use around 100 clay pots of three different sizes to ventilate the building and let in restricted light. The locally made pots have their bottom sections cut off to create an opening at both ends.
Before the pots could be placed on the ceiling, timber sheets and steel reinforcement were laid to create a platform onto which the pots could sit.
Concrete was then poured around the pots creating a 100mm-thick slab. Concrete beams spaced at 1.65m intervals were used to help support the ceiling.
The ceiling spans 10m — a feat achieved despite the notable absence of a structural engineer.
The natural ventilation system works by the warm air rising through the clay pot openings in the ceiling. Fresh and cooler air then enters the library through the unglazed windows.
The window openings are fitted with aluminium louvres, painted in vibrant colours and opened via a steel mechanism. As they open, the louvres fold in half, projecting outwards.
The steel truss system is welded on to the flat steel bars embedded within the concrete beams and the overhanging metal roof is screwed to the truss system. The overlapping metal sheets are raised approximately 1.5m above the concrete ceiling.
The 25m by 7.75m metal roof is raised for several reasons: it ensures indirect light is received through the clay pot openings; it allows the warm air to escape from the interior; and allows for cross-ventilation above the concrete ceiling.