LOOKING TO THE PAST TO BUILD FOR THE FUTURE

The booming construction industry increasingly relies on expensive imported materials to satisfy demand, yet a team of innovative architects believes a solution lies closer to home.

Combining traditional techniques with the latest technology, the only barriers they face are the recently imposed housing regulations, writes Tibebeselassie Tigabu. 

The neighborhoods of Addis Ababa are transforming into concrete jungles, with the mushrooming buildings giving the city a whole new identity.

Many complain of losing their old memories, as the high-rise projects dominate the skyline.

Traditional housing materials such as mud, straw and bamboo are considered “primitive”, now completely replaced by concrete and iron sheets. 

Houses found in different areas of the country, like the hidmos in Tigray or the bamboo houses of Sidama, cannot be transferred to an urban setting, and even in rural areas they are moving towards corrugated iron. 

Many architects criticize the new city buildings and condominium housing schemes as they do not consider the environment, especially regarding the increased carbon emissions. The country is also experiencing a deficit in construction materials, leading to a reliance on imports. 

The scale of construction is increasing, yet the government still faces the problem of its new condominium housing schemes. 

Many people are in desperate need of a place to live, and the backlog of houses indicates the rising demand of the community.

So some architects have proposed the use of environmentally friendly and affordable materials from local resources, such as soil, natural stone, bamboo, and straw, transforming them as an urban-friendly alternative. 

This is the idea of the Ethiopian Institute of Architecture, Building Construction (EiABC). Inside the compound they experiment with different materials in their laboratory/construction site, demonstrating to decision makers and stakeholders the potential for use in housing projects. They also lobby for the revision of the building proclamation, which since 2009 has banned the use of these materials in construction. 

Freedom to express new ideas is practiced, and the ancient housing materials are transformed into new forms, to a point where they are hard to identify.

Mud houses that have sustained generations cannot be built in the city, according to the new building code that forbids permission, but this does not stop the Institute experimenting with the idea. 

Most of the buildings are constructed with the housing sector in mind, limited to two floors and not incorporating high-rise proposals. According to their research the houses work well in two-story form, ideally suited to the density of the ground. 

Helawe Sewunet, an architect and instructor at the institute, believes that these alternative eco-friendly local materials are ideal to use as a substitute to imported products, and will be better for the country’s carbon footprint.  

Bamboo, a material they have dubbed “Green Gold”, has undergone a large amount of research and study at the center. A member of the grass family, it grows rapidly and has long been used in the city for furniture purposes. Fikir Assefa, from the National Bamboo Construction Center, highlights its formidable tensile strength.

One of Africa’s most abundant materials, bamboo has estimated reserves of more than 60 percent, yet it is not used in the cities. The Institute is exploring its potential, and as part of this is constructing a bamboo pavilion in Hawassa town of the Southern Nations and Nationalities Peoples' Regional State.  

Fikir proudly points to the special nature of a grass that survived the Hiroshima atomic bomb, yet if not well preserved and treated can easily be attacked by termites. He is immersed in the abilities of bamboo, and mentions the houses found in Sidama and the weaving plants in Chencha.

It is not an easy material to work with and has to be preserved properly. As it is naturally high in sugar traditional methods include leaning it against a tree for days, felling during the low sugar content season, soaking in mud and water, and smoking over a fire.

Modern techniques see it treated with a formula of borax and boric acid, which in China costs a few cents but in Ethiopia can be worth thousands of birr. 

With the rising cost of housing materials that are not conducive to climate and the dependency on imports, Fikir is convinced that bamboo can provide the answers. With its fast growing nature, abundance of supply, low cost, suitability to all weather and resistance to earthquakes, he believes it should at least be considered as an alternative.

Bamboo houses are common in many countries, and it is even used in the construction of huge structures in parts of Latin America and Asia. Properly preserved the houses can last for hundreds of years. 

Countries that are especially prone to earthquakes encourage the use of bamboo, with housing policies instructing its use for high-rise buildings. 

According to studies, Addis Ababa is prone to earthquakes, and the Great Rift Valley is another potentially dangerous zone. Policymakers have to take all these factors into account when deciding on suitable building materials. 

Accessibility to the raw material is important, like specialist bamboo yards, while knowledge of plant maturity and storage are also vital. 

“The technique of making bamboo houses is different, so training people is necessary, how the arches connect, all the mechanisms,” Fiker told The Reporter. “Knowing the material is important, like where fiber concentration is high. So it needs special training, starting from the grassroots level.”  

Many columns stand inside the compound, and most of the structural work is completed using bamboo, but Fiker says it can be finished with anything, including mud and straw. Around the Mexico area there is a house completely made out of bamboo, and students have incorporated the techniques into their studies.  

The theoretical part was already covered in their education, but practical experimentation with materials such as mud, straw and bamboo was introduced five years ago.

It is not only bamboo that is found in the Institute, there is also a great deal of work with soil or earth houses. Often related to poor or slum areas, they aim to change the attitude of this traditional material.    

According to the Construction Ahead magazine, in collaboration with the Federal Institute of Technology in Switzerland, the earth (mud) house in the Institute was constructed using Rammed earth technology to build the first floor, incorporating a 60cm-wide wall structure. Loam soil was loaded into the form and compressed with small metal ramrods.

The second floor was completed with air-dried loam stones, and the roof was covered with a special mortar. Wall and roof plastering was finished with a combination of a cactus juice mortar, cement and clay. 

According to Helawe at the Institute, the mixes were pre-prepared especially with specific training given to make this form of house. 

Looking at these houses one cannot fail to be impressed with the fine architecture and transformation of the materials. The brown mud house is particularly impressive, and the stone stairs and clay roof gives it an antique look.

Incremental housing is also given attention, with the aim to reduce construction time to just 15 days. Using eucalyptus tree and prefabricate boards, a two-story house is finalized in the compound, and also a model house for Lideta sub city.

According to Helawe, these resources are not processed in a factory, and the cost of these houses is reduced by the availability of the materials in the open market. Also in the Institute is a house made from industrially manufactured straw board panels, compressed with heat. Helawe believes this is the future for an agrarian population, with seed remnants enough for construction.  

Although not revealing the exact cost of the houses as they are for research purposes, Helawe emphasizes the affordability.

When you observe the structures it is difficult to understand why the techniques were not more commonplace before the new building regulations came into force. Helawe thinks it is all linked to a gap in knowledge, and for him one of the challenges is to bridge this gap. 

He proposes to begin training TVET students, while integrating workers who are already familiar with mud and bamboo techniques. He hopes the policy makers will realize the potential and revisit the existing regulations.

Source: Ethiopian Reporter