Our Initial Design
Our focus in this project was to use sustainable resources which are readily available to Haitians, while at the same time making the design both earthquake-resistant and hurricane-resistant. We landed on earthbag construction, a method employed throughout the world and providing just the benefits for which we were looking. Using proper stacking methods, horizontal reinforcement, and a cement-based plaster, the well-constructed earthbag wall is able withstand hurricane forces, but also is able to shift enough during an earthquake to avoid falling in on a building's inhabitants. During the earthquake which hit Haiti in January of 2010, the Sun House, constructed using this method and very close to the epicenter not only survived the earthquake, but did not even sustain any major damage. For more information on earthbag performance during an earthquake, see Bryce Daigle's report.
How the Earthbags Work
We decided to use a modular design, creating two main blocks we labeled a "hard C", a C-shaped building section with square corners, and a "soft C", a curved section with no hard corners. Using these blocks, many different layouts can be achieved with minimal learning. Each block consists of courses of earthbags. To prevent the bags from sliding on top of each other, a couple strands of barbed wire are placed between each course. To provide a structure for the plaster, a series of ties are also placed along each course in order to hold a vertical metal grid (or some other form of this) in place over both faces of the earthbag wall. At the top of the wall, a bond beam ties it all together. A cement or clay-based plaster is then applied to the whole structure.
Bamboo
Currently, we are working out a method to use bamboo as the main material for the flat roof. The main problem is the short lifespan of untreated bamboo - an estimated 5-7 years - which is most likely what would be used in Haiti. So, we are devising a way to manually replace the old bamboo with new pieces. Bamboo will also be used in the construction of furniture and other indoor accouterments.
