Green Building Practices: Ancient Techniques from Around the World
Recent studies have shown that certain architectural and construction methods and materials used 4,000 years ago in Ancient China constitute as Green Building Practices. Parts of the Great Wall of China and the Alhambra Palace in Granada, Spain were both built out of what is called “rammed earth,” a green construction material made from sand, gravel and clay held together with water or other variables.
Using "rammed earth" involves a process of compressing a damp mixture of earth that has suitable proportions of sand, gravel and clay (sometimes with an added stabilizer) into an externally supported frame that molds the shape of a wall section creating a solid wall of earth. Traditional components including lime or animal blood were used to stabilize the material, but cement has been the stabilizer of choice for modern times. To view a short video of an example of a structure made out of "rammed earth," click here.
There is increasing interest in "rammed earth" because it is environmentally friendly and reduces reliance on cement. Manufacturing cement generates 5% of man-made carbon dioxide emissions. One of the significant benefits of rammed earth constructions is its excellent thermal mass; it heats up slowly during the day and releases its heat during the evening. This can even out daily temperature variations and reduce the need for air conditioning and heating.
Adobe, is a building material utilized by communities living in the desert, made from sand, clay, and water, with some kind of fibrous or organic material (sticks, straw, dung). This material is shaped into bricks using frames and dried in the sun.
Similar to “rammed earth,” the adobe material keeps the structure cool during the hot days and warm as the temperature drops at night. In terms of modern times, utilizing this material in construction projects, will significantly reduce energy consumption in the long run.
By its very nature, earth is one of the best sustainable building materials as it is historically the longest used material by man. It is universally a naturally available product, with a heavy thermal mass and a natural barrier to cold winds and forces of nature including insects and rodents. Before electricity, people figured out how to remain comfortable without utilizing an abundance of energy. Today's societies can learn from the techniques and lifestyles of the ancient people by saving energy and building green!
