In Guatemala a technique is used which was invented by Susanne Heisse. Plastic bottles are filled with plastic garbage found on the streets: plastic bags, wrappings, pieces of styrofoam, and so on. The bottles remain light and obtain a slightly higher isolation value. For the construction of the building it is necessary to construct a simple frame, either of wood or concrete. The bottles are fixed within the frame between two layers of chicken wire fencing. The wall is then covered and stiffened with cement mortar.
Because of the climate conditions there is no need for very high isolation values. The bottles are only used as filling to reduce the amount of cement that is necessary to make the walls. There also plays the role empowerment: the school children and people of the neighborhood are involved in the construction of their own school which is possible because the technology is very straightforward and does not involve trained labour. Finally, the participants learn from this how to build structures from on-site resources and garbage.
