Natural and re-purposed materials are fundamental elements of green construction, which are manifest in the form of the building and the building techniques. The majority of our construction materials are from natural or reused resources, and we make every effort to use as few industrially manufactured materials as possible. Natural materials are those which have not been processed and are ‘as found’. These include on-site earth, clay, and lime, pine needles, hay, sand, bamboo, and nopal (cactus). Recycled or re-purposed materials are what might be considered waste, and include car and truck tires, plastic bottles, glass bottles, and inorganic trash. All materials are sourced locally where possible. The cost of materials can be determined when all the site requirements are established, and generally waste and natural materials are free or of little charge.
Construction from tires and rammed earth is beneficial architecturally, as it provides thermal mass and passive thermal regulation. Thermal mass is a measure of a materials resistance to change in temperature. Materials with high thermal mass means that heat travels more slowly, ensuring that the internal space stays cool when the external temperature is hot, and retains the heat when it is cold externally. This negates the need for additional temperature controls such as heating or cooling, as the building naturally maintains an ambient internal temperature.
These structures also have a minimum fire rating of 240/240/240; up to four times longer than typical concrete hollow block buildings. They also withstand seismic events in Zone 5 (Very High Damage Risk Zone) with minimal damage, making them appropriate for areas of high seismic activity.
Using these re-purposed materials for construction minimizes building costs and minimizes building wastes. Constructing cisterns or water catchments on-site, in conjunction with using photovoltaic cells, can make a site self-sustainable; perfect for locations where municipal services are unreliable. Also given these buildings high fire and disaster rating, they are ideal for disaster relief or disaster prevention.
Building with recycled, re-purposed, and waste materials has myriads of advantages beyond just environmental benefits. Involving the local community in the construction process by making trash bottles, collecting glass bottles, tires, and other elements from waste, demonstrates ways that garbage can be appropriately managed and re-used. This encourages people to rethink their perception on trash, as they can physically see the unique things being built from waste; benefiting the whole community and the building site.