The number of Africans living in informal settlements is estimated to be over 200 million. These are the ones continuously migrating from rural to urban areas in search of brighter economic opportunities. In Dar es Salaam, Tanzania, it is estimated that up to 70% of the population lives in informal settlements. These settlements are so poorly designed that even economic, social, and environmental stability is at risk. Nevertheless, Sub-Saharan Africa is among the fastest-growing regions of the world, expanding at 4.5 percent per year. Countries such as Ethiopia, Zambia, and Tanzania are expected to reach 7 percent. The number of Africans joining the working age is expected to exceed that of the rest of the world combined by 2035. This rapid growth in economics and population comes with a significant boom in construction projects across the continent.
Most of them are just the normal brick and mortar buildings, but some dare to break out of the mold and prioritise environmental impact in the construction.
Here are ten greenest buildings that we have identified.
1. Ghana Ridge Hospital
LEED certification is a prestigious rating for environmentally conscious buildings. This is what Ghana hoped to achieve when it commissioned Ghana Ridge hospital in Accra. They had little hope in achieving it though. This is because much of the infrastructure that supports green buildings in US. and Canada, where LEED is most common, is not available in Ghana. The situation called for a rethink of what a green building should be, and, in turn, led to Africa’s first LEED for a healthcare-certified hospital.
The architects, Perkins+Will, improvised for ways to design and build with what was locally available. They first went for natural ventilation, as they couldn’t rely on a complex and expensive HVAC system. They then went on to include outdoor rooms for large groups.
It is also equipped with a solar hot water heater, which is encouraged by the hot Accra climate; this helps curb reliance on electricity. Accra is still a developing city with immense infrastructural and resource challenges, and electricity is unreliable. When the project began back in 2004, the city had a total of 159 days of blackouts in the year. Solar in Ghana Ridge keeps it running in event of the interruptions.
The limited power brings forth another opportunity: the layout of the building. Elevators weren’t possible because of their power draw, so the architects designed a long, stout building. A prominent feature in the design is a fully walkable ramp that connects the four stories.
The building is also not connected to the city’s water supply; instead, all the water used is either trucked in or harvested on site. In the rainy seasons, water is collected and stored in cisterns buried underneath the hospital.
The design of the hospital was inspired by the Kente cloth- an icon of African heritage around the world, as well as part of the local weaving culture in Ghana. Like the cloth, the design makes use of patterning, layering, and vibrant colours throughout the building.
2. The University of Agostinho Neto, Luanda –Angola
The outskirts of Luanda play host to a unique, contemporary institution of higher learning- The University of Agostinho Neto. Defined by an elliptical ring road and a series of courtyards and orthogonal paths that lead to the main court atop the library, the academic village resembles a pinwheel in its master plan.
So what makes this institution’s buildings rank among the greenest in Africa? It was designed with the style of Le Corbusier in mind. The argument being that the minimalist modern style would fit perfectly in Angola.
Innovative strategies were engaged to promote natural ventilation and passive cooling in all buildings except for the library, which is located underground. The existing landscape also played a huge part. The trees were arranged in a linear order to create a funnel through which prevailing winds blow from the southwest. In the opposite direction, the dry savannah draws air through the campus by convection. Heat gains were tackled by the building envelope, which is comprised of brise soleils that reinforce the roof overhangs in a playful, spontaneous pattern.
The second strategy was to position the structures in respect to the wind direction experienced at the site. The classrooms are arranged in a grid that is angled 19 degrees off the north/south axis, thus assuming the ideal orientation to maximize natural lighting and natural ventilation. The roofs of the classrooms are also designed with natural ventilation in mind. They are calibrated through computer dynamics to minimize solar gain, as well as maximize pressure differences to draw breezes through the classrooms.
The library’s upper section is designed with two aspects in mind: to give the structure an iconic appeal as it stands at the center of the campus, and to allow prevailing breezes to flow under it in order to ventilate the classroom structures. With its innovative and cost-effective approach to problem solving, this project is a model for construction of buildings that utilize their surroundings to maximum efficiency.
3. Eastgate Centre Harare-Zimbabwe
Termites in Zimbabwe build gigantic mounds that house their primary food source, fungus. While temperatures outside can range from 35 degrees F at night to 104 degrees F during the day, the fungus must be kept at exactly 87 degrees F. The termites achieve this remarkable feat by constantly opening and closing a series of heating and cooling vents throughout the mound. With a system of carefully adjusted convection currents, air is sucked in at the lower part of the mound, then down into enclosures with muddy walls, and up through a channel to the peak of the termite mound. The industrious termites constantly dig new vents and plug up old ones in order to regulate the temperature.
The Eastgate Centre, largely made of concrete, has a ventilation system which operates in a similar way. Outside air that is drawn in is either warmed or cooled by the building mass depending on which is hotter- the building’s concrete or the air. It is then vented into the building’s floors and offices before exiting the top via chimneys. The complex also consists of two buildings, side by side, that are separated by a space covered in glass and open to the local breezes.
The Eastgate Centre uses less than 10% of the energy of a conventional building its size. These efficiencies translate directly to one conclusion: Eastgate’s owners have saved $3.5 million because of an air-conditioning system that did not have to be implemented. Outside of being eco-efficient and better for the environment, these savings also trickle down to the tenants whose rents are 20 percent lower than those of occupants in the surrounding buildings.
4. Sandbag Houses, Freedom Park, Cape Town, South Africa
The sandbag system, developed by a Cape Town company called Eco-Beam, allows communities to build their own homes using extremely cheap materials. Sandbag houses in Freedom Park were built for only $6,000. MMA architects used inexpensive local materials, therefore cutting down on transportation. In this case, the sand comes from dunes located a few hundred metres from the construction site, and the bulk of the manual labour was carried out by women from the Freedom Park community. Eco-Beam’s system replaces brick and mortar with sandbags. It is said to be a strong, safe, cheap way of delivering affordable housing. Just by looking at the houses, only in your wildest fantasies would you guess that sandbags are stacked inside the timber frames and plastered over.
The project is part of the 10×10 housing project initiated by Design Indaba, which pairs ten teams of South African architects with international designers to pioneer new, affordable housing systems. MMA Architects were initially paired with London architect Will Alsop, though Alsop was not involved in the final design of the houses.
5. Learning Resource Centre, Catholic University of Eastern Africa
This project came into completion back in 2012, and it is an intricate building comprised of a modern conference hall, a bookshop, an extensive library, and a cafeteria. It was designed by an architect named Musau Kimeu. The conference hall boasts of an intricate cooling system where air gets in through vents located at the basement level, passes over well arranged bedrock, where it cools further, and then is released into the auditorium through another set of vents. This is the only rockbed cooling system in Kenya. There are also thermal chimneys located at various intervals of the building that serve the purpose of expelling foul air. There are oxidation ponds for sewage as well. A high-roofed atrium with a narrow plane allows natural lighting to filter through the building. To prevent heat buildup in glazed areas, concrete fins and aluminium louvre screens have been used. It is also oriented for the climate with major windows in the North and South facing walls. Additionally, these are successful in preventing excess glare to the users.
The building above achieves a piece of art and a sense of place that meets the intended function, and lands way above the expectations.
6. African Eco-House – Johannesburg, South Africa
In the heart of Johannesburg, surrounded by ancient oak trees, lies a property which is claimed to be one of Africa’s greenest houses. This is true in every sense of the word. The project is a winner of Enviropaedia’s Eco-Logic Innovation award for pushing boundaries in green architecture. Designed by architect Kenneth Stucke, it took almost two years to complete.
The house was constructed with a purpose of being independent from the town council, by being virtually self sufficient and providing everything it needs for itself. It was also supposed to have a wild garden that reflects a natural high-veld scene and attracts as many birds and wildlife as possible. A wetland had to be added to clean the grey water even further than the filtration through the existing filter systems. All the subsoil drainage water and paving runoff had to be caught up and stored in a natural-looking storage dam with a capacity of 60,000 litres to be used for irrigation purposes.
To achieve this, the previous house in the property was soft stripped, and all reusable materials were given to charity. The remaining mortar elements were then used as backfill to the new house. Strict controls prevented any soil contamination, and all products used on site had to be low in toxicity and VOCs.
The new house has three chimneys, and each have an evaporative cooler on top that pushes air through a wet medium. As the hot, dry air passes through the wet medium, the water evaporates and pushes cool, moist air into the openings all over the house. The stone chimneys are mostly covered by a metal screen. These screens are planted up with creepers and have atomizer sprays inside so that the moist air falls down from the misters and cools the areas of the house that open to the outside.
For the most part, the house is enclosed with greenery. This was done with creepers planted in massive planters all around the house. The purpose of the creepers is to cool down the house in summer, but also to allow the sun in during the cold winter months.
The grey water goes through a two-phase digester system, after the filter system, and falls over a rock face to oxygenate the water flowing through the wetland into the storage dam. Interestingly, indigenous fish species and frogs were also introduced into the wetland area and dam.
What makes this project so unique is that everything is codependent on each other – a small ecosystem that depends on every element to be in good working order. The waste-water system supplies the irrigation system and provides the nutrients for feeding the plants, and the plants have to be healthy in order to provide the comfort and quality of the internal parts of the house. Rather than mechanical solutions that get weaker with time, this system will only improve as the plants mature.
7. Gando Primary School, Burkina Faso
This project was designed in 1999. It was the first building from the architect Francis Diebedo Kere, and it was completed while the architect was still studying. To achieve sustainability, the project was based on the principles of designing for climatic comfort with low-cost construction, making the most of local materials and the local community, and adapting technology from the industrialized world in a simple way. It was also conceived as a standard model that could be copied within the community, and it would raise awareness of the merits of traditional materials.
8. ‘Inno-native’ Home, Accra Ghana
Architect Joe Osae-Addo set a goal to build a beautiful eco-friendly house for his family in Accra, Ghana. He used materials found primarily in rural areas, such as timber and adobe mud blocks. The house has sliding slatted-wood screens and floor-to-ceiling jalousie windows for cross ventilation, which eliminates the need for air-conditioning.
It is raised three feet off the ground in order to take advantage of the cooling, under-floor breeze. Even though the house is connected to the national grid for electricity, solar panels have been installed for backup and to heat water. The house cost $50,000.
9. Woodlands Spa and Forum, Homini Hotel, Cradle of Humankind, South Africa
Here is a bit where green building meets evolution. This beautiful boutique hotel is located on the Letamo Estate in the Cradle of Humankind. It plucks inspiration from the world heritage site’s rich evolution history. The project features a green roof, in addition to concrete retaining and cavity walls, which ensure a high thermal mass. This keeps the building warm during winter and cool during the summer. It also reduces electricity needs by almost 75%.
With an intention to not disturb the environment and the wildlife, the Woodland Spa and Forum has integrated itself with it’s surroundings; in fact, reclaimed bricks have been used for the construction, small game can graze on the roof, and indigenous plants are used in the gardens. The intricate inter-connectivity between architecture, landscape, and history makes Woodlands Spa a property to behold.
10.El Mandara eco-resort, Fayoum, Egypt
This resort was previously a series of rundown buildings, and it has now been renovated by a group of young people who saw its potential. They advocated the use of local, sustainable building materials including mud bricks (a la Hassan Fathy) and palm fronds to provide shading from the relentless desert sun. It sits astride Lake Qurun and pays deep respect to its natural surroundings.