3D printed homes in Kenya: A future blueprint for affordable housing?

A 14 Trees 3D printed building under construction.

A 14 Trees 3D printed building under construction.

Interview with François Perrot

Lives in: Madrid, Spain

Just outside the town of Kilifi on the Kenyan coast, approximately 70 kilometres north of Mombasa, stand 10 houses. These homes are the first phase of the 52-unit Mvule Gardens development, claiming to offer residents a family-friendly lifestyle in a peaceful neighbourhood. “A home where you can live life to the fullest and make your most treasured memories,” reads the marketing pitch.

Yet, these are no ordinary homes. Rather than built by hand using conventional methods, they were printed using a giant 3D concrete printer.

The company behind the project is a for-profit startup called 14 Trees. Its investors are Holcim, a Swiss-based building materials company, and British International Investment, the UK’s development finance institution. Established in 2016, with a mission to commercialise affordable and eco-friendly construction technologies, the company first focused on sustainable building bricks. However, in 2020 it pivoted to 3D printed buildings, initially using a printer from another manufacturer to construct houses and schools in Africa. This year, 14 Trees announced the launch of its own 3D printing technology, manufactured in Johannesburg by a local outfit called Pan Mixers South Africa.

François Perrot

The newly introduced 3D concrete printer, named Iroko, utilises a special concrete – made by 14 Trees’ investor Holcim – to build structures layer by layer. Its aluminum frame is light and quick to assemble, allowing it to be mounted without cranes and stored in a container, enabling easy transportation and deployment.

In an interview with How we made it in Africa, François Perrot, the managing director of 14 Trees, explained that the cost of building with the 3D printing technology is currently comparable to conventional construction methods. However, he anticipates a 20% cost reduction over the next 18 months as the company utilises its own printers, introduces new designs, and benefits from cheaper raw materials.

As environmentally-friendly buildings become more of a thing in the construction industry, one of 14 Trees’ key selling points is its buildings’ lower CO2 emissions compared to standard cement production methods. The real estate sector is responsible for nearly 40% of greenhouse gas emissions, with substantial contributions from the manufacturing of raw materials, packaging, and transportation. 14 Trees claims its method can reduce a building’s carbon footprint by up to 70% in comparison to traditional processes.

According to Perrot, the company is able to construct the walls of a house within half a week. The entire process, from the initial excavation to adding the roof and painting, takes about one month.

14 Trees' 3D concrete printer

14 Trees’ 3D concrete printer

The company has two primary revenue streams. The first involves constructing 3D printed projects, either for clients or as part of its own developments. For example, the company has constructed a school in Malawi for a major international organisation, while for its Kenyan housing project, it has purchased the land and is responsible for building and selling the houses. However, Perrot notes that these projects are primarily aimed at showcasing the technology. The second, and potentially more significant revenue stream as the company expands, will be the sale of its 3D printing hardware and software to other construction firms.

While the aim is to market its solutions worldwide, Perrot emphasises that Africa will continue to be a key focus for the company. “It will remain a very important market for us, in particular for house construction – 2 million houses are needed in Kenya, [in] Nigeria its more than 10 million houses,” he says. He hopes to soon replicate the company’s Kenyan development in West and North Africa.

Perrot points out that one of the company’s key challenges is getting its technology approved within different countries’ building regulations. Additionally, he acknowledges that convincing homebuyers to adopt such a novel technology can be difficult, as purchasing or building a house is often an emotionally charged decision. Due to this, he finds that the technology is generally more easily accepted for projects like schools and warehouses, where emotional factors play a lesser role.