2024 - Bottles of life: sustainable and healthy toilets

In Northern Cameroon, precarious sanitary conditions due to unsanitary toilets put residents in danger. Inadequate sanitation infrastructure increases the risk of water-related diseases. The region’s extreme heat increases these problems, compromising hygiene and public health. It is essential to raise awareness about the importance of sanitation and take measures to improve the quality of life of residents.

The ”bottle of life” aims to introduce low-cost sanitation solutions by recycling plastic bottles to use natural light in developing countries. This promotes sustainable development and fights bacterial diseases such as cholera, polio, typhoid and hepatitis by installing recycled bottle roofs on public toilets. Plastic bottles offer weather resistance and thermal insulation ideal for arid climates subject to prolonged periods of drought, this is also managed, among other things, by earth walls (rammed earth).

In our project, we mainly favored the use of local materials such as rammed earth, iroko and plastic bottles. This approach aims to minimize the carbon footprint linked to construction while promoting the involvement of the local workforce and craftsmen. Through this commitment, we nourish the regional economy by actively supporting local businesses and industries.

In addition, not only is the building accessible to everyone, regardless of gender, but it has also been designed for people with disabilities, particularly those in wheelchairs.

-Elements fighting against microbes

– Plastic bottle roofs:
Turning plastic bottles from landfills into Roman tile-style roofing slates requires several steps. First, the bottles must be thoroughly cleaned and then cut into sections. Then the slates are assembled using staples and tape, before being fixed to the roof by cutting them to size. Finally, it is recommended to install a support beam along the edge to prevent destabilization of the roof due to water.

– Elimination of micro-organisms:
The method relies on the use of UV rays from the sun to eliminate pathogenic microorganisms from water. UV rays penetrate through transparent plastic bottles damaging the genetic material of microorganisms, rendering them harmless. Approximately 6 hours of exposure is necessary to eliminate pathogens and reduce the risk of water-related illnesses. This method is simple, inexpensive and effective, suitable for regions where access to drinking water is limited. Additionally, the space is well lit, and adequate thermal insulation maintains a cool temperature in the building.

– Use of rainwater (also helps with the sanitation problem):
Gutters protected by recycled metal grilles in North Cameroon filter debris during rains. Water passes from pipes to recycled plastic tanks, eliminating microorganisms with the help of sunlight. The water thus treated is transported to homes for domestic use. In the event of insufficient rain, a company can fill the tanks. This innovative system ensures a supply of clean water and is part of an ecological and sustainable approach.

-Elements fignting against the heat

– Window :
Using iroko wood windows and pre-cut bottles, the hot air comes into contact with the plastic bottles, undergoing compression which makes it come out cooler. This process uses natural evaporation to cool the interior without electricity. This economical and environmentally friendly solution offers an ingenious way to maintain a pleasant temperature inside buildings.

– Rammed earth walls (and help for sustainable development):
Rammed earth, an ancient technique, is used in the north of Cameroon. Mixing clay soil in wooden formwork (30cmx50cm) and compactor, rammed earth walls offering a unique aesthetic thanks to the pigments. To reinforce seismic resistance, steel reinforcements can be integrated. Ecological and durable material, requires less energy than concrete or bricks. Featuring excellent thermal and acoustic insulation properties, helps reduce the air conditioning and heating needs of buildings. Additionally, regulates internal humidity, promoting a healthy indoor environment. Well-maintained earthen structures can have a long lifespan, enhancing the sustainability of buildings. Finally, the warm and natural aesthetic of rammed earth walls adds charm and authenticity to constructions made with the material.

-which evacuates the air:
Toilets must be well ventilated to evacuate unpleasant odors. In this building, circular openings at the top of the adobe walls ensure effective ventilation.

– why use iroko
Iroko, a wood originating from northern Cameroon, excels in its resistance to climatic variations and its aesthetic appeal. Very popular, this versatile material is widely used in construction for durable and modern buildings.

Again, some decoratives elements made in wood and rods are also used on the outershell of the building to create movement.