Senegal’s Petite Côte (small coast) is the stretch of Atlantic frontage, just south of Dakar, with shimmering white beaches that are cooled by constant trade winds, and shaded by towering cocoa palms and lofty kapok trees. It is in this locality that a unique local residence conjures up the modern glass house, but with a local accent.
Khamsa House was the dream of a client who wanted a home that provided a natural oasis and social gathering place. All that was requested was a modern house with two bedrooms and large open space for entertaining friends, several water features, and views that overlooked the existing natural landscape.
Atelier Koé, a Dakar based architecture practice that focuses exclusively in architecture constructed of mud/earth brick, was given extraordinary freedom, a total carte blanche. The firm built Khamsa, Arabic for the number five, with a series of oval symbols meant to symbolize warding off the evil eye and keeping the peace.
According to Richard Rowland, principal of Atelier Koé:
“Khamsa”, the eye in the hand, recognized as a sign of protection is the symbol we played with in the design process.
The project concept revolves around the notion of connection and transition, from inner to outer, from light to shadow, from public to private, from reflection to absorption, from dry to wet, from social to intimate.
The site featured some great older palms and acacias at the periphery and some other newly planted indigenous fruit trees, all of which were kept intact. The house and out buildings (garage, utility room, guard house) as well as the swimming pool/jacuzzi were all placed amongst the existing landscape so as to minimize disturbing what was already there and to maximize views.
The floor plan was arranged to open up to, and have unrestricted views of, a massive pool which incorporated a natural filtration system, eschewing chlorine and chemicals by treating the water in a smaller pond lined with plants.
What makes the house unique is its raw material – mud. While a vast majority of builders in the area utilize more traditional, modern building techniques, this home is green from the ground up. The earthen retreat is formed from bricks made from the soil on which the home was built.
The machine that formed the clay bricks even utilized earth dug out to make the curving basement and the pool, building walls out of the readily available raw material. There was virtually no waste of building materials or space.
Earth building has been going on successfully for 11,000 years, so why should it stop or be replaced by concrete (which is really a new building material in the scheme of things)?
The construction utilized compressed earth bricks stabilized with 8% Portland cement for the main house and poured earth for outbuildings. On one small outbuilding, they experimented with poured earth walls– with a dual stabilization of cement and lime—which creates a very different aspect and texture. Given the encouraging results, Rowland hopes to experiment further with this in future projects.
The walls, which are thicker than those used in standard concrete construction, help moderate the interior temperature in a region where the climate swings from dry to humid throughout the year, absorbing humidity and cooling the home during warm weather while moderating temperature and improving indoor air quality.
Inside the home, toxic-free lime plaster walls create a cool, calming effect while breathing in the same manner as the earthen bricks, helping to regulate the interior climate. The 16-inch high dropped ceilings also contribute to more consistent airflow, allowing for natural air ventilation and insulation in addition to a dramatic perspective.
The custom casework for the kitchen was built by local artisans. The room exemplifies the fluid interior-to-exterior transitions that are a hallmark of Rowland’s design.
Insulation is provided via poured Earth on the roofs, topped with a heat reflective waterproofing paint. The natural pool’s water is circulated through an adjacent plant basin where the roots of aquatic plants filter bacteria and debris, eliminating the need for chemicals.
The plants in turn create an ecosystem which attracts dragonflies, frogs and other insects that eat mosquito larva. A solar water pump is necessary to keep the water aerated and circulating for a minimum of 8 hours a day. The designers recommended algae-eating fish to take care of algae fluctuations in the very hot months.
After a few months, when the plants are more mature, the pool will stabilize and self-regulate, requiring very little maintenance.
The 3,800-square-foot home, whose thick, “breathing” walls of earthen brick absorb humidity and cools the interior, is also self-sustainable, thanks to rooftop solar panels and wind turbines. The hybrid production is harvested in the same battery storing units. The installation is calibrated to be self- sufficient with the sun, while the wind acts as a bonus by recharging the batteries while the sun is out. The home also boasts a Jacuzzi with pumps powered by the rooftop solar panels.
The benefits of this house to both the owner and the environment are many. As a model for ecological living, it provides the owner with a modern, self sustaining, of the grid home with a small environmental footprint. The cost of construction was 15% less than conventional houses, and the local populated benefited from jobs that would otherwise be performed by machinery.
Ultimately, the thinking process is that we are creating a sane and healthy habitat which is beautiful and functional, but because it’s made from earth, can one day go back to where it came from– either to be recycled into something else or absorbed back into the earth naturally. That’s a pretty powerful concept when you think about it. We feel like too many structures go up without thought to final recycling or the impact the building has on the local (and global) environment.
All photographs © Régis L’hostis and Richard Rowland