What we do

Techniques we use - how they work
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Earthbag
Material: Any type of soil

Used for thick load-bearing walls, the earthbag technique works with a wide varieties of soils including low clay ones. Bags (typically polyethylene rice bags) are filled with damp earth, laid in rows and compressed by tamping. Barbed wire is laid between each course to strengthen the wall. It is the only technique that makes dome construction accessible to beginners. Bags also work as foundation for small buildings (gravel filling).

  • Technical level
  • Construction speed
  • Insulation
  • Materials costs
  • Labour costs
  • Load-bearing capacity
  • Durability

Straw bale
Material: Straw

Piled over each others, straw bales act as large bricks providing a very high thermal insulation (typically U≈0.1) both to the walls and the roof. The standard size of the bales has to be considered while designing the wood frames, but bales can also be used as a load bearing material without the use of columns. If protected from rain and rodents, straw bales can last up to 200 years.
  • Technical level
  • Construction speed
  • Insulation
  • Materials costs
  • Labour costs
  • Load-bearing capacity (without wood)
  • Durability

Slipstraw
Materials: Straw/Clay

Long straw is mixed with a small amount of liquid clay and stuffed between panels, then compressed and left to dry. For the same thickness, slipstraw is nearly as insulative as straw bales and can be used to fill thinner interior walls too. Yet, compared to straw bale building, slipstraw is time consuming (construction and drying time) and isn’t load-bearing (has to be used inside a wood frame).

  • Technical level
  • Construction speed
  • Insulation
  • Materials costs
  • Labour costs
  • Durability

Adobe
Materials: Earth/Sand/straw

If not mechanized, the production of adobe bricks is labour-intensive and time-consuming. Yet an adobe wall can support heavy loads and can serve as a thermal mass to store heat in winter or cool down the interior on hot summer days. Its insulative power (except in the case of very thick walls) is very low. Protected from water, adobe lasts many centuries.
  • Technical level
  • Construction speed
  • Insulation
  • Materials costs
  • Labour costs
  • Load-bearing capacity
  • Durability

Cob
Materials: Earth/Sand/straw

Despite using a mix similar to adobe, cob is not shaped into bricks but applied directly by hand, allowing walls to be modeled like sculptures without constraints other than structural ones.
The high plasticity necessary for cob requires long drying times which limits the daily growth of walls. Once dry, cob can be as durable and strong as adobe bricks.
  • Technical level
  • Construction speed
  • Insulation
  • Materials costs
  • Labour costs
  • Load-bearing capacity
  • Durability

Plasters
Materials: Earth/Sand/straw/lime/Oils/Egg/Flour/Pigments

Plasters give a building its character and protect it from rains, winds and animals. It is a crucial step in the building process and should be taken seriously. The lifespan of a building will depend widely on the quality of its plasters. Producing quality plasters such as straight rough coats, beautiful earthen finishes or waterproof tadelakt lime plasters requires much experience and skills.
  • Technical level
  • Construction speed
  • Materials costs
  • Labour costs

Woodwork

All buildings contain wood in some form or another, therefore any project will require woodworking to some extend. Wood is the only natural building material that can be used for both its compressive and tensile strengths: it is effective against both vertical and lateral pressure. The anti-seismic efficiency of well built wooden structures has been proven throughout history. Although not as long-lasting and cheap as earth-based materials, wood is often a preferred material, especially for roofing.
  • Technical level
  • Construction speed
  • Materials costs
  • Labour costs
  • Load-bearing capacity
  • Durability