A humanitarian project designed by F8 Architecture in collaboration with Gérard Violante on a plot of two acres 50 km south of Bamako, Falatow Jigiyaso Orphanage clearly illustrates how the traditional building codes of the sub-Sahelian region can be adapted to the extreme conditions of a desert climate.This rather modernist orphanage complex offers accommodation for children and staff with toilet and shower blocks, a small medical center, administration offices, a kitchen and a dining hall. Classrooms and terraces are located on the first floor for children’s activities. The blocks are arranged around a central yard, an acknowledgement the courtyard houses of traditional Malian and West-African architecture.
The site is located within a Sub-Sahelian area that experiences extreme hot and dry weather conditions. Due to the restricted budget, the architects could not employ air-conditioning units to achieve thermal comfort for interior spaces. The solution was to incorporate passive design strategies from the onset. They based the whole design of the orphanage on three innovative strategies that would guarantee livable spaces in the building despite the extreme fluctuations of the external temperatures.
The first strategy was to reduce solar heat gain. This was achieved by having a double roof; corrugated iron sheet roofing on steel trusses elevated over a flat roof using columns. The iron sheet roofing overhangs creating deep balconies that also protect walls from direct solar insolation. The space created between the elevated iron sheet roof and the flat roof is used as a terrace for children’s activities.
The second strategy involved increasing the thermal mass and consequently the thermal lag of the walls. The solution? To construct external walls using hollow of “H”-shape concrete blocks that are then stuffed with Banco: a mixture of mud and grain husks. Banco has excellent thermal insulation properties and is readily available in Mali. In addition, for the west facing facades gabion cladding is employed since they are most exposed to the hot afternoon sun. Crushed rocks held together with wire mesh are placed on walls to create a double wall, greatly improving their thermal mass and improving the building’s overall materiality.
The final passive design principle involved improving natural ventilation. This is achieved firstly by arranging the various blocks about a central courtyard. Each block is then equipped with several vent grills that facilitate cross ventilation across the complex to cool interior spaces, eliminating the need for air conditioning. These passive design strategies are very effective with an indoor-outdoor temperature difference of up to 20 degrees during warm seasons.