To achieve low cost eco-housing we have to be creative in the methods, as well as materials, that we use to build houses. Compressed Earth Block construction has been around for many years and has been particularly used for low cost construction in the majority world (like Africa and Latin America). However it is just as relevant in the rest of the world and several companies are seeking to expand its use in countries like the United States. EarthCo Building Systems have developed an EarthCo Megablock which uses a machine onsite of a build to compress local soils into giant modular blocks. They call their ‘EarthCo MegablockTM machine’ a ‘modern factory on wheels’.
Placing a newly made Megablock during the construction of the Mariposa eco-village welcome centre, USA
The group argues that it is cost effective because it “saves on the cost of construction materials — onsite materials are basically free and eliminate most if not all transportation costs. Megablocks go directly from manufacture to a wall system (moved only once) eliminating inefficiency in the process. No storing, shipping or multiple handling of Megablocks is required. Saves energy required for construction — unlike concrete, steel, and wood construction methods that consume large amounts of energy during mining, harvesting, processing, shipping etc. This system requires a small amount of energy to process raw earth into a GCEB block and place it mechanically into a wall system. This results in the lowest embodied energy costs of any building system worldwide”. Cost is not the only advantage though, they also argue that it is time and labour efficient, mobile, durable and highly adaptable.
Walls and complete Mariposa eco-village welcome centre, USA
There is also a very interesting piece which outlines the history and low cost uses of compressed earth block by Wayne Nelson of Habitat for Humanity. Habitat seeks to eliminate housing poverty and homelessness from the world and to make decent shelter a matter of consciousness and action. What is particularly interesting about these types of methods are their prevalence in majority world countries, often advocated by non-governmental organisations from the minority world (such as the US and Europe), and yet how relatively little we have incorporated such methods into our own building styles. Are we capable of learning lessons from low cost housing projects in continents such as Africa, or are we better at exporting our green building ideas than we are at changing building methods in our own countries?