We are living in a world with a growing awareness about the harmful impacts of toxic chemicals in our life. Though highlighted rarely, the same rule holds true in the field of construction. A majority of what are considered to be "modern building materials" are harmful for the health of either the users, or the manufacturers - and definitely the environment.
Therefore, we stress on the use of natural, energy intensive materials in construction - such as mud, lime, stone, mud bricks, timber and so on. Not that, but we strive to have all treatments to these materials done naturally, free of toxic chemicals.