University of British Columbia tests mushroom-powered toilet that turns waste into fertilizer

Researchers at the University of British Columbia (UBC) have unveiled what they describe as the world’s first mushroom-powered, waterless toilet designed to turn human waste into compost and fertilizer.

The prototype, called the MycoToilet, is being tested for six weeks at UBC’s Botanical Garden. It uses mycelium — the underground root network of mushrooms — to break down solid waste and absorb odour-causing compounds.

According to Steven Hallam, a professor of microbiology and immunology at UBC, laboratory tests showed that the mycelium liner absorbs about 90% of odour compounds while drawing out moisture and supporting aerobic decomposition. “The breathable mycelium liner can reduce odour while removing residual moisture, limiting the onset of anaerobic conditions and creating more favourable conditions for decomposition,” Hallam said.

The waterless system separates solids and liquids, with the solid waste processed in a mycelium-lined chamber. The modular unit requires only four maintenance visits annually and is expected to generate about 600 litres of soil and 2,000 litres of liquid fertilizer each year once fully operational.

Project lead Joseph Dahmen, an associate professor at UBC’s School of Architecture, said the goal was to reimagine the design and user experience of composting toilets, which are often associated with unpleasant smells. “We wanted to show that a waste-separating toilet doesn’t have to be a sacrifice to use,” Dahmen said. “It can be a really beautiful experience that connects us to natural ecologies.”

The small cedar-clad structure features prefabricated timber panels, a skylight, a green roof supporting native plants, and a low-power fan for air circulation. One user described the experience as “like a Scandinavian sauna,” according to Dahmen.

Hallam said the installation serves as a “living laboratory” where researchers will monitor how different fungi species affect the toilet’s performance over time, potentially offering new sustainable waste management solutions.