Building Decarbonisation in the Construction Industry: our focus for the Small Business Innovation Research Project (SBIR)

6 min readSep 14, 2022


Training the local team at KAYEC how to build with Polyblocks.

In April 2022, we applied and won funding for a competition looking for aspiring entrepreneurs and innovative ideas on: “Design and innovate with locally available materials for economic and environmental impact.” The Small Business Innovation Research Programme (SBIR) is funded by the Netherlands Enterprise Agency (RVO).

There are (were!) exactly 5 months between project awarding and project completion. That is a very ambitious time frame to implement the vision. Nevertheless, our team is always up for a challenge and together with our partners, we are managing to complete the project’s milestones in an impressive speed.

The Project is focusing on:

  • Innovation
  • Local context and local solutions for African Countries
  • Local network and partnerships
  • A solid Business Case based on End-user and (public) buying clients
  • Gender equality and involvement of women

Material and Building Circularity through Deep Tech and Adaptive Architecture in Southern Africa​

Our successful application has allowed an exciting three phased project to unfold and come to life with our main project partners Advanced Environmental Design Initiatives Africa (AEDI), NCS Resin and Polycare Namibia. Our existing manufacturing operations in Namibia and strategic expansion plans for South Africa decided our regional focus area.

In this 1st phase of the pilot project, we want to prove that transforming the built environment into a circular economy and decarbonising the construction sector is possible. We are implementing a practical solution of how to design and innovate with locally available materials for improved economic and environmental impact. By sourcing material waste streams to manufacture Polyblocks to build adaptive structures designed for disassembly and reassembly, we want to make the case that the built environment can become part of the solution to lowering greenhouse gas emissions.

Driving a systematic transformation of the construction and building industry

The project is about a field pilot to prove a systematic transformation of the construction and building industry: Secondary raw and waste materials are turned into high-quality building blocks (material circularity) designed for reuse and repair (building circularity). The project follows major paradigm shifts:

a) Integrating useful secondary material streams into the blocks, that would otherwise end up in landfills.

b) Design for Disassembly: Deconstruct instead of destruction, reuse through circular and adaptive architecture.

c) Business Models for Circularity: Promoting repair to extend the lifecycle of the components to the maximum and turning circularity into an economic advantage.

This article will be focused on the material circularity aspect of this project. We will shortly publish a piece on the building- and design circularity approach — which of course can not be seen in isolation.

The Material Source

Spent Foundry Sands

Spent foundry sand

One of Polycare’s core values is to #thinkcircular. We are looking at both, material and building circularity concepts to enable a holistic circular approach to building and construction. Our recipe and production process allows the use of any flowable materials as filler — including secondary raw materials (in contrary to the conventional concrete brick which requires precious and scarce sand). According to the Department of Forestry, Fishery and the Environment, South Africa is sitting on a R45billion (EUR2,6billion) waste industry. Mines, foundries and energy providers are producing by-products such as slags, fly- and coal ash and spent foundry sands that currently end up on dumps. According to the industries, it is becoming increasingly expensive and compliance-heavy to dispose of those materials. Many of them have been classified as non-hazardous and safe for reuse. Legislation is constantly being improved and developed to support the beneficitiation of those “waste” materials. According to the South African Institute of Foundrymen, foundries are looking for innovative ways and partners to manage their spent sands. We see this as a great opportunity for the building industry, and our product, to transform those materials into beautiful building blocks.

Manufacturing the blocks in their casting moulds

For the purpose of this research project, we secured a sample of “green” spent foundry sand from a South African foundry in Gauteng. Due to their organic compounds, green spent sands can be regarded as non-hazardous and are safe to use in building materials. Together with our material partners NCS Resins, we undertook a feasibility study of the materials in their lab in Durban to find a suitable recipe to make our blocks. After 3 days, about 20 test trials and successful compressive strength tests, we were confident to have found a winning recipe. Besides maximising the % of secondary filler materials in the blocks, NCS Resins have also invested a lot of work to develop a polyester resin with almost 30% recycled PET content, and is used in this recipe. If you know anything about the polyester resin industry, you’ll know how unique that is — the product is called Earthkind Resin.

Team members in Namibia
The final blocks formulated from Earthkind resins and spent foundry sands.

South African Foundry Sands in Namibia

It was not sufficient for us to have proven material circularity on a lab sample. We want to actually produce real-size blocks to build a real-size building. That is why we transported the sands to our factory in Namibia to produce the blocks. And it was a great success. It took the team 2 weeks to clean, sieve and produce about 14 tons of building blocks — which are currently being used to build the KAYEC Test Tower in Windhoek.

Drawing of the tower to be built up at KAYEC Youth Training Centre September 2022.

A team made up of a local contractor, engineers, planners, builders and Polycare Namibia are currently constructing a four storey structure at the KAYEC Youth Training Centre in Katatura, Windhoek, Namibia. Once completed (planned for next week) we will hold the inauguration and networking event to bring together stakeholders equally passionate about building circularity in the construction sector. Watch out for a future post on more details around the concept of adaptive architecture and circular building as part of this project.

Building circularity and adaptive architecture

Through this project, we are not just showcasing the use of smart, alternative building materials​ but also how important it is to take into consideration the complete construction value chain in circular building approaches. We must not just look at the lifecycle of building materials but of the entire building. Principles around adaptive architecture and “designed for disassembly” become key in this endeavour.

Taking the “sand” back to South Africa

The KAYEC Test Tower in Windhoek has been designed for disassembly. After serving its purpose for a couple of months, we will disassemble the structure and transport the blocks back to South Africa. The tower was also not designed in isolation to its environment. The site is adjacent to a soccer field and the foundation casting will remain behind and used by fans wanting to watch their teams play on weekends. Trees will be planted for shading purposes. The tower building blocks will be reused in a different design typology: an off-the-grid training pavilion, linked to the Centre of Ecological Intelligence at the University of Johannesburg.

We are convinced that circular is how we build our future together. In South Africa we are gearing up for Phase 2 of this project. For more updates on this specific project, follow us on LinkedIn.

“The constant happiness is curiosity.” — Alice Munro




To drive empowerment and circular economy, Polycare develops innovative construction technologies, that make sustainable habitats affordable.