Building on the Edge
Climatic construction guidelines for emerging cities of Ethiopia - The case of Addis Ababa
According to the current figures, Ethiopia is currently one of the fastest growing economies in the world.1With more than 80% of the population living in the rural areas; the recent economic growth can be seen clearly in countless emerging new towns and rapidly expanding cities. Consequently, the current urban centers in Ethiopia including the capital city of Addis Ababa are facing massive pressures of rapid urbanization. One of the challenges is how to build these new urban centers since different cities need their own contextual approach. Therefore, this project uses climate responsive design approach to provide building design guidelines by taking Addis Ababa as a case study.
The project uses analytic step-by-step, test and design methodology to come up with the guidelines. In the initial test phase, three building prototypes built by the EiABC [Ethiopian institute of Architecture Building construction and City Development] are investigated to study the climate suitability of different construction materials and designs. The buildings are called: SUDU [Sustainable urban dwelling unit] rammed earth construction; SECU [Sustainable emerging city unit] straw panel with timber construction; and SICU [Sustainable incremental city unit] combined precast concrete and timber building.2 These buildings were selected for the analysis because of their approach to provide alternative construction technologies to the conventional fully concrete based approach. The results provided mainly quantitative values for each building`s thermal comfort and daylight performance.
The major findings showed that for thermal comfort, a building envelope with high thermal mass is required since the major climatic challenge of Addis is the daily temperature swing, which can reach up to 20 K in the summer months. In terms of daylight, the climate analysis showed that the dominant sky condition throughout the year is an overcast sky; therefore, window daylight design needed to be based on diffused daylight condition.
Findings from the climate analysis along with series of the building investigation results were used to formulate the final climatic design guidelines for Addis Ababa, which include concepts on building massing and orientation for passive heating and cooling, properties of a suitable building envelope along with design recommendations for efficient daylight design.
The current massive development and construction taking place on Addis especially on the city edges, gives opportunity to test and implement the new guidelines in actual building projects. Therefore, a design proposal for the eastern edge of Addis, one of the major expansion areas in the city, is included as an example of how the different guidelines could be incorporated into a new building.
This project is based on the city of Addis Ababa and the design strategies formulated are for the climatic conditions of the city, but the project`s long-term goal is to adopt this step–by-step design and test methodology of investigating local building materials and construction systems with the climate to come up with contextual design guidelines for new cities in Ethiopia.
Project mentors: Jochen Lam, Matthias Rammig
Fasika Sahlemariam Gebremeskel
Fasika Sahlemariam Gebremeskel graduated in 2012 with a BSc degree in Architecture from the EiABC - Ethiopian institute of Architecture Building Construction and City Planning at Addis Ababa University. Then as Assistant Lecturer under the Chair of Building Construction he was involved in teaching and research.