Sustainability has many faces. These three pillars are particularly well known: environmental protection (planet), economic viability (profit), and social equity (people). For our holistic approach in providing school infrastructure, all of these pillars are important: efficient use of resources, equal access to education, and building according to local environmental standards and possibilities.
In our projects in Guatemala, we work together with a fantastic organization called Esperanza e.V. – we are glad to partner with them since they are focusing on building schools in a way that conserves energy and resources: Economical use of energy and raw materials, the use of ecological and regional building materials and a recyclable, climate-adapted, economical construction method. In doing so, the materials used are mostly clay or bamboo. As a general rule, to construct a two-story building with earthquake resistance, the upper floor should be a light construction. Walls in lightweight construction are built by a supporting structure of bamboo tubes filled with a wattle of reeds and a clay throw. The wattle and daub is a traditional construction method and is called "Bahareque". This method of construction is beneficial for adding stories to existing concrete block buildings.
What makes these two materials – clay and bamboo – so unique? And why do we refer to them as being sustainable? Unlike cement, which is very energy-intensive to produce, clay can be extracted from the ground in the immediate vicinity. Its extraction consumes very little energy. Recycling clay mixtures is also generally possible without significant effort. An essential property of clay is its positive influence on the indoor climate. Due to its physical properties, clay can regulate the room climate particularly well. If it is too humid in the room, the installed clay absorbs the moisture. If it is too dry, it rereleases it. Likewise, it can bind pollutants and thus purify the air in the room. It functions as a natural AC.
Bamboo is an extreme product of nature in size, lightness, and strength. It is also referred to as vegetable steel. Its structure and properties correspond to a highly modern high-tech material: it is stable but extremely light and elastic thanks to its cavities. It is reinforced by the partitions and has physical properties superior to other building materials such as wood, concrete, or steel. Within one season, the bamboo stalk grows out entirely and "lignifies" within 5-7 years. While wood has a hard core and becomes softer on the outside, bamboo is hard on the outside and soft on the inside - a much more stable structure. In the highlands of Guatemala, wood is also not sufficiently available or very expensive.
You see, these two materials make an excellent match for the schools built in Guatemala.
Just like here in Guatemala, we always try to use locally available resources and make a school construction as environmentally sustainable as possible.