Local materials and techniquesThe challenge of limited resources for this project became an opportunity. We managed to respect a short supply-chain of building materials and labor force, supporting local economy, and installing pride in the construction of a library with the poor people’s material: earth.Earth analysis: “field tests and laboratory tests” - Raw earth as building material is more fragile than other conventional building materials. Some analyse is thus important to do. Some easy tests can be made on field to have a first idea of its quality. Some other tests have to be made in the laboratory to have a beter understanding of the material and improve its performance.CEB: “from mother nature” - After an extensive material research in relation with the context, it was decided to use compressed earth bricks (CEB) as the main material for the construction of the building. We were lucky enough to find 2 CEB machines intactly under 15 years of dust. The Terstaram machines produce earth blocks of 29x14x9cm that are very similar to the bricks we know in the North, apart from the fact that they are not baked. Four people are constantly producing stones, up to 1100 stones/day.Eucalyptus “wood; the strongest, the reddest” - The load bearing beams that are supporting the roof are made of eucalyptus wood, which is sustainably harvested in Muramba. Eucalyptus wood renders soil acid and therefor blocks other vegetation to grow. Thus, a clear forest management vision is needed to control the use of it in the Burundian hills. When rightly managed, Eucalyptus is the best solution to span spaces and use as construction wood, due to its high strengths and fast growing.Tiles: “local quality product” - The roof and floor tiles are made in a local atelier in the surroundings of Muyinga. The tiles are made of baked Nyamaso valley clay. After baking, their color renders beautifully vague pink, in the same range of colors as the bricks. Each roof surface in the library design consists of around 1400 tiles. This roof replaces imported currogated iron sheets, and revalues local materials as a key design element for public roof infrastructure.Internal Earth plaster: “simple but sensitive” - Clay from the valley of Nyamaso, 3 km from the construction site, was used for its pure and non-expansive qualities. After some minimal testing with bricks, a mix was chosen and applied on the interior of the library. The earth plaster is resistent to indoor normal use for a public function, and has turned out nicely. Bamboo: “Weaving lamp fixtures” - Local bamboo is not of construction quality, but can nicely be used for special interior design functions, or light filters. In a joint workshop with Burundians and Belgians, some weaving techniques were explored, and in the end, used for the lamp fixtures inside the library.Sisal rope: “from plant to hammock” - Net-making from Sisal plant fibres is one of the small micro-economies that bloomed in this project. It took a lot of effort to find the only elder around Muyinga that masters the Sisal rope weaving technique. He harvested the local sisal plant on site, and started weaving. In the pilote project, he educated 4 other workers, who now also master this technique, and use it as a skill to gain their livelihood. The resulting hammock serves as a children’s space to play, relax and read, on a mezzanine level above the library space.Concrete “when it’s the only way out” - For this pilot project, we didn’t want to take any risks for structural issues. A lightweight concrete skeleton structure is inside the CEB columns, in a way that both materials (CEB and concrete) are mechanichally seperated. The CEB hollow columns were used as a “lost” formwork for the concrete works. It is our aim, given our experience with Phase 1, to eliminiate the structural use of concrete for future buildings.