A BusinessWeek article bemoaning the lack of coherent standards in the ‘Green’ industry. Rammed earth is highlighted as an example of a product which, while pushing its sustainable credentials, does not appear to have a national or international standard by which it can be judged.
I would agree with this premise. Aside from the lack of structural design guidelines, there is also a lack of acknowledgment of the true sustainable nature of rammed earth.
For example, rammed earth is often quoted as being excellent in controlling both the relative humidity and temperature within a building, but there are very few (and conflicting) studies to back this up. I hope to be able to resolve the relative humidity debate soon – watch this space. The issue of using only the materials around you is also called into question if the material used for rammed earth must be sourced offsite – a recent project in the UK transported clay the length of the country in order to obtain the correct rammed earth mix. A sustainable building technique done in an unsustainable manner.
If rammed earth is to be considered a sustainable building material, in addition to producing advice on the structural and thermal behaviour, the relevant bodies should also include some aspect of sustainability in any guidelines they produce.
(and this is before we even consider the question of cement in rammed earth)