The Art that is 3D Printing

3D-printed House No. 0 by 14 Trees in Athi River, Kenya Photo Credits: Construction Kenya.

Given the estimated housing deficit of approximately 50 million housing units in Sub-Saharan Africa[1], innovation and creativity must be applied to fuel the delivery of housing units at scale and at affordable price points. To this end, new technologies have been developed to resolve the issue of overcrowded unsafe housing by producing units that have faster construction, lower costs and sturdier materials to aid delivery of housing units at scale and within affordable pricing points especially for the low- and middle-income earners. One of the technologies gaining traction in the housing space is 3D Printing. Is it possible to print a building? Yes, it is! The innovation is a valuable, rapid, and economical solution that brings a digital object into its physical form adding layer by layer of materials.

What is 3D printing? Step by step, 3D printing of housing structures happens by first designing a model on a computer. Specifications are then used to “print” the material, typically concrete, that forms walls and design attributes, placed over a pre-built foundation. The concrete is rolled out via thousands of “layers” that produce the walls, causing a rigid surface that can later be smoothed over.[2] 3D printing is also referred to as additive manufacturing as the object is built from scratch. Basically, the process works by laying down thin layers of material in the form of liquid or powdered plastic, metal, or cement, and then fusing the layers together. However, the printers lack the capacity to create a fully functional house as only frames and walls are built and other features such as windows, electricity and plumbing are installed separately.

Although 3D printers employ a variety of techniques and materials, they share the ability to turn digital files containing three-dimensional data (whether created on a computer-aided design (CAD) or computer-aided manufacturing (CAM) programme, or from a 3D scanner) into physical objects. 3D-printed houses are created using very large 3D printers that can extrude concrete, or other building materials through nozzles, to gradually build up a 3D object the size of a house.

3D printers are said to have come into the market in the seventies, however, the adoption of the technology especially in the housing sector has been witnessed in only a few countries in Europe, North America (such as the Unites States and Mexico), and only recently in Africa. In Malawi, a public-private partnership between the British government and 14Trees, an affordable housing provider, has constructed two consequential 3D projects: a home and a school. The construction of the school was completed in under one day.[3] For homes, 14Trees achieved a construction cost of USD 10 000, compared to the USD 19 083 cost of building a standard home in Malawi.[4]

In 2021, 14 Trees also announced a 3D-printed 52-unit affordable housing project—Mvule Gardens Project to be built in Kilifi County in Kenya—marking the successful deployment of 3D printing technology into the Kenyan construction market. The development will have 1, 2 and 3 bedroom units of 42 SQM to 76 SQM and priced at Ksh 2.436m (USD 21 437) to Ksh 4.484m (USD 39 459).[5] This works out to approximately Ksh 58 500 (USD 510)[6] per SQM, compared to the Kenya government’s affordable housing price guidelines of Ksh 50 000 per SQM (440)[7] and the current residential market pricing of approximately Ksh 119 494 (USD 1 052)[8] per SQM.

As 3D printing continues to gain traction in Africa’s housing space, other parties working in the space include: General Electric’s Lagos Garage which provides training in advanced construction and engineering techniques, including 3D printing in Nigeria; and Buni Hub in Tanzania, a tech centre that is building 3D printers.

The main benefits of 3D printing include:

• Rapid Prototyping – This is the use of 3D printers in the design process to create prototypes. 3D printing can manufacture or prepare housing part within hours, which speeds up the prototyping process. In addition, to saving on time, 3D printing is estimated to be approximately 70% cheaper than standard construction[9].
• Print on Demand – The 3D design files are all stored in a virtual library as they are printed using a 3D model as a CAD (Computer aided design). This means they can be located and printed when needed. Edits to designs can be made at very low costs by editing individual files without investing in tools.
• Sustainable and Environmentally Friendly – Production of parts only requires the materials needed for the part itself, with little or no wastage as compared to alternative methods which are cut from large chunks of non-recyclable materials. The process saves on resources and reduces the cost of the materials being used. The environmental benefits are extended through a reduced carbon footprint given the improved fuel efficiency from using lightweight 3D printed parts.
• Flexible Design –The technology can produce very complex shapes that would be otherwise impossible to construct by hand, including hollow parts or parts with internal truss structures to reduce weight.
• Customisation – 3D printing personalizes products according to individual needs and requirements. Even within the same build chamber, the nature of 3D printing means that numerous products can be manufactured at the same time according to the end-users’ requirements at no additional process cost.

Just like any other process, this technology does have its downsides. First, 3D technology reduces the need for human labour, since most of the production is automated and done by printers.  In many African economies, a focus on housing construction is in-part a job creation strategy.  This technology could put construction jobs at risk by significantly reducing the need for human labour.

Secondly, 3D printing concrete cannot be reused which means more demolition waste, coupled by the environmental destruction caused by resource extraction for concrete, resulting in open pits which are not often rehabilitated. Printed housing units are not flexible and thus do not allow for incremental building which is quite popular especially among the low- and middle-income earners.

Furthermore, there is the cost of the purchasing the printers and getting them to the construction site, noting the bulky nature of the machines. Finally, it is important to note that 3D printing only address one arm in the delivery of housing units: the construction cost of the unit. All other related costs which include land, design, planning, infrastructure, and statutory costs remain.

On the brighter side, there will be an increased need for engineers to design products and fabricators to develop and produce the printers. In addition, the adoption of the technology will demand technicians to maintain, use and repair the 3D printers. This will support job creation and the overall economy thus mitigating against job losses. Developers are also orchestrating ways of minimizing negative effects of the 3D technology especially the concern on reduced need for human labour. According to CDC Group, the 14 Trees projects will sustain skilled job creation by hiring and upskilling local experts in roles such as 3D machine operators to material specialists, and working in partnership with local builders for carpentry, roofing, and painting.

That said, while 3D-printed homes are not yet mainstream, the continued advance of this technology spells promise for the housing sector in Africa, given the huge housing deficit and the need for delivery of affordable housing units at scale. However, further innovation is still required to ensure sustainable solutions are sought, noting the need for use of eco-friendly solutions which include reduced use of concrete.

[1] Tiwari Saurabh (2022). CDC Group: How CDC supports access to housing in Africa and South Asia. 1 February 2022. https://www.cdcgroup.com/en/news-insight/insight/articles/access-to-housing/

[2] Beyer Scott (2022). Catalyst: 3d Printed Homes: A Fix for Global Housing Problems? 23 September 2021. https://catalyst.independent.org/2021/09/23/3d-printed-global-housing/

[3] CDC Group (2022). World’s first 3D-printed school opens in Malawi 23 June 2021. https://www.cdcgroup.com/en/news-insight/news/worlds-first-3d-printed-school-opens-in-malawi/

[4] Beyer, Scott (2021). Catalyst: 3d Printed Homes: A Fix for Global Housing Problems? 23 September 2021  https://catalyst.independent.org/2021/09/23/3d-printed-global-housing/

[5] See https://mvulegardens.com/

[6] 1 Kenya Shilling = 0.0088 USD

[7] Centre for Affordable Housing Finance Africa (2022). Kenya’s Affordable Housing Programme: Delivery framework overview. 20 November 2019. https://housingfinanceafrica.org/app/uploads/AHP-Brief-Presentation-Feb-2019.pdf

[8] Cytonn Investments (2022). Cytonn Annual Market Review 2021. 2 January 2022. https://cytonnreport.com/research/cytonn-annual-markets-review-2021#real-estate

[9] Beyer Scott Catalyst: 3d Printed Homes: A Fix for Global Housing Problems? 23 September 2021  https://catalyst.independent.org/2021/09/23/3d-printed-global-housing/