A 29-year-old Kenyan woman is turning discarded plastic into paving bricks, successfully addressing the growing problem of plastic waste in her community while creating a sustainable and affordable alternative building material for the construction industry.

Based in Nairobi, Nzambi Matee is a trained engineer with a background in physics and materials engineering, and a passion for creating sustainable solutions. She is also the founder of a startup, Gjenge Makers Ltd that uses a composite of recycled plastic waste and sand to produce a line of eco-friendly pavers.

The company has partnered with manufacturers of plastic bottle tops and seals in the beverage and pharmaceutical industries in Kenya to source offcuts and scraps. Additionally, they work with informal waste collectors who deliver discarded single use plastics for use in the production of pavers, making Gjenge Makers a social enterprise that provides livelihood to many in the community.  

Operating from a small workshop in Nairobi, Gjenge manufactures plastic pavers on a prototype machine developed by Matee, with the business churning out 1,500 paving stones a day. Currently, the products find a market among homeowners and schools because of their affordability and durability.

“It is absurd that we still have this problem of providing decent shelter – a basic human need,” said Matee. “Plastic is a material that is misused and misunderstood. The potential is enormous, but its afterlife can be disastrous.”

Matee’s motivation to launch the business came from the need to find a solution to the immense problem of plastic waste strewn along Nairobi’s streets. Quitting her job in 2017, she spent the next three years in a small lab set up in her mother’s backyard, creating and testing pavers using a combination of plastic and sand, and trying to find the correct mix through trial and error.

An opportunity to attend a social entrepreneurship training programme in the United States of America allowed her to use the material labs in the University of Colorado, Boulder, to further test and refine the ratios of sand to plastic. She also developed the prototype machine that would be used to make the bricks.

“Once we know how to make one paver, we need to know how to make 1,000 pavers,” she explained.

Gjenge pavers are fully certified by the Kenyan Bureau of Standards. They have a melting point over 350°C, and they are much stronger than concrete pavers.

Matee was also a winner of the 2020 Young Champions of the Earth prize, announced by 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.

Soraya Smaoun, who specialises in industrial production techniques with UNEP, said, “Nzambi Matee’s innovation in the construction sector highlights the economic and environmental opportunities when we move from a linear economy, where products, once used, are discarded, to a circular one, where products and materials continue in the system for as long as possible.”

Images: Gjenge Makers Ltd