Ugandan innovator turns agricultural waste into cement-free earth bricks for cheaper homes
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Makerere-trained quantity surveyor Leslie Kaneene is developing CoolBricks, a bio-stabilised earth brick that replaces cement and firing with local soils and farm waste, and is now being tested through the Housing Finance Bank Zimba Challenge.
Leslie Kaneene, a quantity surveying graduate of Makerere University, is developing CoolBricks, a construction technology that uses locally available soils and agricultural waste to produce bio-stabilised earth bricks, in a bid to lower the cost of building a home in Uganda.
The process eliminates conventional cement as a stabilising ingredient and avoids energy-intensive firing, an approach intended to deliver a more affordable, lower-carbon alternative to conventional building materials. The project targets reductions of up to 50% in construction costs and up to 90% in carbon emissions, targets whose significance will depend on how the bricks perform outside the research environment and how the results compare with conventional methods.
Having refined the material through academic research and early pilot projects, Kaneene is using the Housing Finance Bank Zimba Challenge to test the innovation against the practical demands of housing delivery, including affordability, adoption and the ability to scale. His work has involved testing different soil compositions and biopolymer formulations, supported by collaboration involving Makerere University and Delft University of Technology in the Netherlands.
"Ideas alone are not enough. Execution is everything. A solution only matters if it can survive contact with reality, cost constraints, material limits, and human behavior included," Kaneene said. He argues that a material may be inexpensive to produce, but that advantage means little if it cannot deliver the strength and durability required for safe, permanent homes.
The ambition extends beyond brick-making. CoolBricks envisages decentralised production hubs that would bring manufacturing closer to communities and construction sites while creating opportunities for local enterprises, youth employment and skills development, and would create potential markets for agricultural by-products that might otherwise go unused.
Kaneene also points to financing as a separate barrier, noting that cheaper construction does not automatically make homeownership affordable and that households still need arrangements matched to their incomes. He sees potential in rent-to-own models, potentially developed with institutions such as Housing Finance Bank, as a complement to lower-cost construction.
Uganda's housing deficit was put at about 2.48 million units, with the shortage expected to remain a major challenge as the population and urban centres grow. Lands, Housing and Urban Development Minister Judith Nabakooba said at a recent housing sector dialogue that the country needs about 300,000 new housing units annually to reduce the deficit, against current production of about 60,000 units, and that housing should occupy a central position in national development planning.