With her Nairobi-based startup company Gjenge Makers, Nzambi Matee produces cheap and lightweight bricks from recycled plastic and sand.
by Likam Kyanzaire
Concrete is considered one of the most destructive materials on Earth, and its widespread use has significant environmental consequences. The production of cement, a primary component of concrete, generates a significant amount of carbon dioxide (CO2) emissions, contributing between 4-8% of total global CO2 emissions. Concrete has a significant negative impact on the environment.
Cement production is a complex process that also generates other environmental impacts such as air pollution, water pollution, and soil contamination. After the cement is produced, it is then mixed with an aggregate composed of sand, gravel, other materials, and water to make concrete. The aggregate used in the production of concrete is typically sourced from local bodies of water and can have a negative impact on aquatic ecosystems. Additionally, the production and transportation of concrete require significant amounts of energy and contribute to greenhouse gas emissions.
If we are serious about sustainably managing our environment then we need a more environmentally friendly building material. Enter Nzambi Matee. Young, ambitious and incredibly talented Ms. Matee is the winner of the Young Champion of the Earth 2020 Africa award at the United Nations Environment Programme (UNEP). The award “provides seed funding and mentorship to promising environmentalists as they tackle the world’s most pressing challenges.”
With her Nairobi-based startup company Gjenge Makers, Nzambi Matee produces cheap and lightweight bricks from recycled plastic and sand. Gjenges plastic bricks have been used in community projects like the Karai Munsingen Children’s Home, but in time we may be all walking on plastic.

Kenya’s Nzambi Matee
Concrete Kingdoms
Concrete is one of the most widely used building materials in the world and is ubiquitous in modern construction. It is used in a variety of applications, including residential and commercial buildings, bridges, roads, dams, and other infrastructure projects. In fact, concrete is the second most consumed substance on Earth, after water.
The widespread use of concrete is due to its durability, strength, and versatility. It can be moulded into various shapes and sizes, and can also be reinforced with steel to increase its strength. Additionally, concrete has a long lifespan and requires minimal maintenance, making it a cost-effective option for many construction projects.
Despite its advantages, concrete also has significant environmental impacts, as discussed earlier. As a result, there is growing interested in developing sustainable alternatives to traditional concrete like plastic, which can help mitigate its environmental impact while still meeting the demands of modern construction.
Plastic is Sustainable
According to Our World in Data, the Great Pacific Garbage Patch (GPGP) alone comprises 1.8 trillion pieces of