Innovation Scales down Housing Cost

Published on 28th August 2007

From construction of European Union offices in the pastoral areas of North Eastern Uganda, public buildings such as schools and offices to ordinary dwelling structures, the use of compressed earth bricks (CEB) is gradually sweeping through Uganda like a wild bush fire.

This earth brick architecture is not only environment friendly (by avoiding the massive depletion of wood fuel used to fire the bricks and its resultant atmospheric pollution) but also utilizes locally available human and material resources: artisans, metal fabricators, sand, murram while optimizing industrial products like cement. Equally important is the training and involvement of the local artisans, improving housing conditions for local populations and employment creation.

The technology entails fabrication of metal compressors manned by human labor to mould bricks out of a combination of earth (murram), and 5% cement which are sun dried for just a week.

Through successful pilot projects, demonstrations and sensitization, the mentality that using un-fired bricks is a poor man’s alternative, has been conquered. In fact, the earthen technology is gradually being incorporated into the formal curriculum for technical institutes including the department of architecture of Makerere University. In response to Uganda government’s strategy of helping local populations to be more involved at constructing and maintaining public infrastructure, Makerere University’s Department of Architecture initiated a program aiming at implementing earthen architecture in their syllabus to fit with the policy.

A feasibility study was also carried out with a country based Rukararwe Partnership workshop for Rural development (RPWRD) to establish how earthen architecture could solve the deforestation problems, resulting from sprawling building construction activities. It was established that building construction was one of the factors responsible for deforestation in Uganda. Most public buildings are made of locally fired bricks that consume a minimum of 16 cubic metres of wood fuel (an amount needed to fire the necessary quantity of bricks to complete a single classroom). Fired brick is the material everyone aspired to use for building their house. If this dream were to be fulfilled, it would entail tones of wood fuel.

Both institutions accordingly contacted CRATerre –EAG, a French organization specialized in earthen architecture, for support and contribution towards their objectives through a specific program.

Prior to this initiative, the majority of the population in rural areas lived in wattle and daub houses made of timber frame structure –in-filled with earth. The life span of such a structure was estimated at 25 years due to degradation of the timber structure .Thus for the housing stock to be maintained, a lot of timber would be required to keep refurbishing the structures.

The study identified problems associated with the mud and wattle houses as high consumption of wood (thus deforestation), limited life span due to rotting of the timber which is directly in touch with the ground, lack of stability due to absence of bracing in the construction and costly cement plastering which does not stick to the earth walls. On the other hand, the high cost of using of fired brick technology made it difficult for constructions and completion of buildings.

Accordingly, compressed earth bricks were proposed for the program recognizing that a CEB wall of good quality is 20% cheaper than a fired brick wall of equivalent quality. It was realized that tree planting initiatives alone would not help to restore the vegetation unless complemented with alternative measures to dissuade people from cutting trees. This led to promoting a technology that entailed building structures without cutting trees.

A number of technical teachers and students from various institutions have had on site training in areas of production, site identification, quality control, construction process, identification of raw materials and rural structures design among others. Currently, the types of buildings are answering Ugandan standards in terms of quality, durability and maintenance needs.

The director of RPWRD Mr. Samson Nyine Bitahwa says the range of cost per square metre of living space is between 45 to 55 Euros compared to 60-70 Euros per square metre of conventional technologies of similar quality. Based on local materials and skills, maintenance is more affordable. The technology ensures that use of fired bricks is reduced by a minimum of 52 percent, hence reducing deforestation. A number of artisans have got employment and are using the acquired skills to improve their own dwelling houses.

Bringing together different local actors to take charge of monitoring the project has led to the spread of the building experience hence the actors are able to replicate similar projects in other districts. The quality of the materials provided by local production units is acceptable. Locally supervised production is a manifestation that the construction techniques promoted by the project are now mastered locally. One of the trainers Abel Bishoni says a group of 18 masons are capable of completing a standard classroom in a month including the making and drying of bricks, construction and roofing.

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