Tuesday, 12 April 2011

Sandbag Houses, South Africa

Sandbag House, Cape Town (image: metropolismag.com)
 
A truly sustainable building is one which uses local labour and local materials for its construction. One fantastic example of such a building or buildings are the sandbag houses built in Freedom Park near Cape Town, South Africa. Designed by MMA Architects, this is a pilot project of 10 affordable housing units being built to house people living in shanty housing. Due to the nature of the building system (timber and sand) and the method of construction (labour carried out by local women), the housing is very cheap to build - 65,000 Rand (£4,300) per unit. The main labour force for the project are local women from Freedom Park, and the sand used for construction is readily available a few hundred metres from the site. 
(image: metropolismag.com)
Sandbag House close-up (image:inhabitat.com)
The houses use a sandbag construction system called "Eco-Beam" which was developed as a way to provide low tech, low cost housing. A large part of the construction can be carried out by lay-persons since it does not require much expertise. The method consists of three main elements: a timber framework of Eco-beams (timber and metal beams which create the shell within which the sandbags sit); geo-fabric bags filled with sand; and cladding material (usually wire mesh with plaster, timber or plasterboard).

Sand as a material is heavy which provides many desirable environmental qualities. Once complete, the buildings is waterproof, fireproof and soundproof and has good thermal qualities. Alongside being cheap in terms of materials, this method of construction also saves money in terms of time spent on site. The building can be erected fairly quickly since it is a dry method of construction (no cement, concrete etc.). Since sandbags do not restrict the shape of the buildings, theoretically any shape is possible for this method of construction as long as the framing has been designed accordingly.


Check out the video below for more information about this construction method (yes, the video is not excellent quality, but you get the idea...)


In a country like South Africa, where sand is readily available, it makes sense to take advantage of such easily accessible (and free!) materials. Not only is there a reduction in transportation which is a big component of carbon emissions in construction, but the simplicity of the construction method allows for the future residents to become a part of the building process and gives them a sense of pride over their achievements. This can also be a great way to build community ties through the shared ownership over a certain area. Alongside this, it allows the local people to contribute towards the construction of their dwellings and therefore instilling in them a sense of responsibility and duty and perhaps also providing them some work in the meantime. 


For more information about the project see dezeen, metropolismag and inhabitat. For information on the Eco-Beam method see Earthbagbuilding and Ecobuild

3 comments:

  1. make sure clean soil is used. there has been reports where seeds started growing in the bags and damaged the walls.

    ReplyDelete
  2. Good point, thanks for your comment!

    ReplyDelete
  3. We are starting a self-help community housing project and we would like to build some of the houses with this model. I would like to know more about the model. leslie@umnotho.org.za

    ReplyDelete