Friday 25 March 2011

Natural Building

Whilst researching for more traditional skilled methods of building and materials I came across an ecovillage called Dancing Rabbit Ecovillage, situated in Rutledge near Memphis in the USA. This ever growing group of people build their own houses, in an aim to live sustainably and responsibly within modern culture, using traditional techniques powered by with renewable energy from the sun and wind. 


Traditional craft is becoming more and more popular due to the ever increasing demands of eco friendly buildings and reusable materials. The majority of the materials used in traditional craft are locally sourced and natural, meaning that they meet these needs. We are beginning to see an incline in traditional crafting methods in building and constructing for these reasons.


The basic materials which are used by the ecovillage are earth, wood and straw. Depending on the climate, as well as the type of craft used, the materials can be combined to make a natural home. This is how the Dancing Rabbit Ecovillage build their natural homes which incorporate traditional craft. They explain their methods and materials:

  • Strawbale - Strawbales can be stacked to make the walls of a house. We have created both load-bearing (roof supported by the bales) and non-load-bearing straw homes.
This is an example of a strawbale house built by the Dancing Rabbit Ecovillage
  • Cob - Cob is a mixture of straw, clay, and sand similar to adobe but lumps of cob are applied wet to build up a wall, bench, or as thermal mass around stoves.
This is an example of a cob building
  • Light-Clay Straw - Also called, clay-slip straw, clay is mixed with water until it is the consistency of paint and then is mixed with straw until every straw fiber is coated. The Straw-clay is then packed into forms or wall cavities for insulation.
Light-clay straw walls
  • Wattle and Daub - Wattles are made from flexible wood or fibers and are woven loosely to create an underlying structure for a wall (imagine a loosely woven basket). Plaster is then daubed onto the wattle to finish the wall and provide thermal mass.
Wattle & Daub wall being plastered
  • Natural Earth Plaster and Lime Plaster - Most of the above techniques are finished off with a natural plaster. Earthen plaster is made from clay, sand, and straw (or sometimes other fibers such as cattail fluff or manure). Lime plaster is made with sand, hydrated lime, and sometimes fiber (straw, animal hair, etc.). Lime is made by heating limestone in a kiln and has been used since ancient times. Lime plaster is much more weather proof than earth plaster but has less embodied energy than cement stucco.
  •  Rubble Trench, Urbanite, Gravel Bags, and Frost Protected Foundations - One of the trickiest parts of natural building is the foundation. We have used a few techniques to minimize the amount of concrete used in our buildings (concrete has high embodied energy and produces greenhouse gases in its production). For a rubble trench we dig down to the frost line and install a drain pipe in a gravel filled trench. Water flows out the pipe and the trench foundation therefore can't "frost heave" from water expanding as it freezes. To build the foundation up above the ground level we have used Urbanite (reused broken up concrete) and gravel bags (polypropylene bags filled with gravel). While the bags are plastic and thus not very natural, their embodied energy is low when considered as a durable part of a house. We have also insulated many of our foundations to protect them from freezing which allows them to be shallower and use less material.
  • Earth Floors - Also called adobe floors, an earthen floor is made from the same material as cob or earth plaster and is troweled to a smooth finish. It is then oiled, which hardens it and allows it to be swept and mopped.
An earth floor being laid
  • Timber Framing - Timber framing is an old natural building technology which uses heavy timbers and joins them using mortise and tenon construction techniques rather than smaller wood and nails or screws. A timber frame wall can then be filled in with straw bale, light-clay straw, cob, or any number of materials.
Diagram showing different parts of a timber frame
  • Thatch - Thatch is used throughout the world for walls and roofs. We have experimented with using native prairie grasses for thatching with some success.
A close up of thatching
  • Adobe - Adobe, like cob is made from straw, clay, and sand but is sun dried into bricks and then stacked to form walls. It is generally finished with an earth plaster
Adobe bricks being dried in the sun
  • Rammed Earth - Earth can be pounded into forms to create massive walls to form a house. While utilizing minimal resources it can be very labor intensive.
A building showing the different colours of a rammed earth wall
  • Living Roof - A living roof allows plants to grow on top of a roof. Soil is placed over a waterproof membrane on an extra-sturdy roof. The soil and plants can help keep a building cool in summer and warm in winter by evapo-transpiration, thermal mass, and insulation.
An example of a traditional living roof

1 comment:

  1. Sustainable living needs to be achieved by as many an adventuring saoul as possible to preserve a way of life that has nearly been forgotten by so many of us city dwelling folks. Where do I sign up? Better yet, who is willing to go in with me on some land and start living the right way? The way that The Creator expected us to?

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