OA 026 zero energy house | rammed earth

Rammed Earth might look like the “ultimate luxury” however it’s made from earth. The Chinese wall was made from this material. Rammed earth resist thousands and thousands of years. It’s made from sand, gravel and clay. In the past they added stabilizers like lime and animal blood. Nowadays the most frequent stabilizers used are lime, cement and asphalt.

Problems. The insulation. It might work in Spain and in Africa … however in the Northern hemisphere you have to insulate it. Check these materials for a flawless insulation. I would use rammed earth for inner walls to support the roof for example. However granite is way batter to store the heat. Granite works way better when you want to put a water tank within the inner walls. Rammed earth is quite easy to use. If you have this type of earth in your area then it’s quite cheap to use as well. Don’t forget to insulate the rammed earth walls underneath. Read the (30/30/30) rule. Put 20-60 cm layer of wood underneath the walls. Between the walls and foundations. How great an idea … Yes…all of the engineers will try to kill me here. I love this part. The engineer will hate you for that. I love this part the most.

When they say it can’t be done and “we” do it. Over and over again. Using wood as an insulation between the foundations and walls will stop most of the heat transfer. Your monthly heating bills will literally disappear because of “details” like this. This way the concrete/stones from the foundation won’t transfer the cold from the earth to your walls. Most of the people say: yes but the earth is warm. Yes it is. Now go and look at your monthly heating bill again. Needless to say in warm climates of the Mediterranean, Spain or Florida you don’t need insulation or wood. In this climate rammed Earth will heat up during daytime and will radiate the heat back in the nighttime. So when the temperatures are low your walls will slowly release the energy captured directly from the sun. For further explanation read about the thermal mass.