UBC launches world’s first mushroom-powered, waterless toilet

UBC researchers have launched the world’s first mushroom-powered waterless toilet, the MycoToilet, at UBC Botanical Garden. The prototype turns human waste into nutrient-rich compost using mycelia—the root networks of mushrooms—and features a modern, sustainable design that can be dropped into parks, remote communities and areas without plumbing.

“We wanted to turn a daily routine everyone knows into a pleasant experience that reminds us of our connection to ecological cycles,” said Joseph Dahmen, associate professor at UBC’s school of architecture and landscape architecture (SALA) and project lead.

“Composting toilets often carry negative associations. We aimed to create a system that’s clean, comfortable and easy to use.”

How the MycoToilet works

At the back, a system separates liquid from solid waste. Solid waste enters a mycelium-lined compartment, where fungi absorb odours and microbes break it down into compost.

“Fungi are very good at breaking down biomass, including human and animal waste,” said Dr. Steven Hallam, professor in the department of microbiology and immunology. “They produce enzymes that transform material into simpler compounds while supporting microbial communities that accelerate decomposition. No added water, electricity or chemicals are required.”

Researchers will study how microbial communities interact with the mushrooms to optimize aerobic waste breakdown and avoid the odours common in anaerobic composting. Lab tests suggest mycelium liners remove more than 90 per cent of odour-causing compounds.

Sustainable design, ready to drop in

The modular toilet requires just four maintenance visits a year and is wheelchair-accessible. “From an operations perspective, this is streamlined by design,” said Prof. Dahmen. “We’ve taken out the uncertainty that can scare municipalities away from composting toilets and solved it—the schedule is set, the ventilation is integrated, everything works as it should.”

Unlike conventional chemical toilets, which contain formaldehyde and other chemicals that require treating waste as toxic material, the MycoToilet offers a safe, environmentally friendly alternative that also prioritizes user comfort and hygiene.

Prefabricated timber panels form the structure, while a cedar exterior is naturally rot-resistant and charred for antimicrobial properties. A green roof supports local plants and wildlife and a low-power fan keeps air circulating.

The skylit building blends into the forest near UBC’s tree walk. A ramp leads visitors to the entrance, where timber and stainless steel finishes, along with a ventilated cedar structure and odour-absorbing mycelium compartments, replace the typical look and smell of composting toilets.