Description

What are the benefits of rammed earth construction?

It is the oldest building material of the world, and it is almost forgotten ! Buildings made of rammed earth are back on the agenda when it comes to ecological habitations… But why ? Let’s check the various benefits of rammed earth:

• Natural material found in abundance in most places: it has no bad impact on health, it does not pollute, and it does not produce any waste.
• Economical: It is possible to build a house  by yourself, using soil, straw, water and sun.
• Thermal and acoustic insulation is very efficient.
• Breathable: With a finish coat made of  lime.
• Aesthetic and unique: Each house made of earth is, like an artwork, the produce of its artisan’s creativity.

What are we exactly talking about?

Different methods of earth-made construction are available (excerpt from the article “Building a house made of rammed earth”) 

• Rammed earth (See the video above for an example): A mixture of clay and sand, sifted and moistened. Successive layers of rammed earth are superimposed between wall forms, and then compacted with a pestle.
• Cob: The soil is  cleaned of rocks, and then mixed with vegetal fibers (sometimes animal) and water as to maintain the cohesiveness of the mixture.
• Adobe: Mud bricks made of earth mixed with vegetal fibers, molded and sun-dried.
• Earth blocks: Rammed earth slightly humidified, then compressed  using a mechanical press and stored under tarps.
• Wattle and daub: Mixture of earth and fibers used within a wood frame.

It is essential to know the clay content of your earth (by doing a sedimentation test for example). For a soil to be an efficient binder, it must be composed of 15 to 35% of clay.

What king of constraints may you face?

The two main disadvantages of rammed earth construction are:

• Implementation: It takes time, workforce and  know-how.
• Legislation: In some countries rammed earth buildings are not authorized due to a lack of understanding.

For further information:

• Bibliography in Spanish and English about natural construction: caminosostenible.org
• “Building with Earth”, 1991, CRA Terre (in English)

Video (in Spanish):

Seen at

Name		Type of facility	Environment	Country	Swap?
	Terra Barichara Hotel	Hotels & guest houses	rural, zone-chaude	Colombia	Yes
	Casona Distante Ecolodge	Hotels & guest houses	rural, zone-temperee	Chile	Yes
	ASTURS & Inti Wasi Lodge	Community based tourism, Hotels & guest houses, Packages and tours	rural, zone-temperee	Peru	Yes
	Wasipunko Ecolodge	Hotels & guest houses	rural, zone-chaude	Peru	Yes