Could a process that uses mycelium to help recycle old buildings into new ones solve the problem of the city’s many abandoned homes?

Over 7,000 abandoned or condemned homes litter the urban landscape of Cleveland, Ohio, where a stunning population loss of about 100,000 residents in 25 years and widespread foreclosures have sparked a housing crisis marked by growing racial and economic disparities. Posing concerns in terms of economic stability, public health and safety, the abandoned homes that line many of the city’s streets are at once symbols of its resilience and ongoing obstacles to growth and prosperity.

Cleveland native Christopher Maurer, founder and principal architect at local humanitarian design firm Redhouse Studio and adjunct professor at Kent State University, has plenty of ideas about how to address the city’s complex challenges.

The ultimate goal is to be able to make new buildings entirely out of old ones Christopher Maurer

Inspired by the work of inventor Philip Ross and his company MycoWorks, Maurer argues that one of the keys to addressing Cleveland’s housing crisis lies in an unlikely source: mushrooms. Specifically, in using mycelium – the vegetative part of a fungus – and Cleveland’s other “natural” resource, construction waste, in a process called “biocycling”, which essentially recycles old buildings into new ones using plant materials.

“I like to refer to Cleveland as ‘ground zero’ for biocycling,” says Maurer, who believes the city has the perfect conditions and challenges to serve as a prototype for the process.

The Cityscape: get the best of Guardian Cities delivered to you every week, with just-released data, features and on-the-ground reports from all over the world

Widespread demolition is often touted as a means of solving many of Cleveland’s ills, including violent crime rates. In 2017, in response to the discovery of the body of a 14-year-old girl, Alianna DeFreeze, in a vacant home in Cuyahoga County after she was abducted on her way to school, the mayor, Frank Jackson, unveiled a demolition programme as part of his Healthy Neighborhoods initiative. The city allocated $5m last year for the demolition of 500 vacant homes –primarily on Cleveland’s east side – within 500ft of public schools.

Facebook Twitter Pinterest An empty lot where a crumbling home was demolished in East Cleveland. The pylons were left to keep vehicles out. Photograph: Paul Sobota/The Guardian

But many critics say demolition isn’t enough and doesn’t get to the root of Cleveland’s complex housing challenges, particularly poverty and racial inequality. Around 36.5% of the Cleveland population live in poverty, and there was a 24% increase in family homelessness from 2015 to 2017, leading to a troubling irony: despite empty homes everywhere, thousands of Clevelanders are homeless.

Given the complex obstacles Cleveland faces in the housing market, using mushrooms to rebuild may seem strange, but it’s actually part of a growing trend called mycotecture, or architecture using mushrooms and fungi. “Demolition waste is one of Cleveland’s raw materials,” Maurer says, “and the philosophy of biocycling is about doing something with what we already have rather than generating even more waste.” About 9,000 homes have been demolished in Cleveland in the last 12 years, and building with mycelium-based materials and other living organisms, he says, could serve as a viable way to make good use of the aftermath.

Facebook Twitter Pinterest Construction debris is ground to a pulp and combined with biobinders, then pressed and treated to make bricks and other materials. Illustration: Redhouse Studio

Biocycling combines construction waste and debris with “biobinders” (natural glue or cement) like fungi, plant materials and microbes to create new building materials. In practice this means that onsite construction waste such as wood and insulation is ground up into a pulp and mixed with plant materials, which are allowed to grow in place. The resulting “bioterials” are then pressed and treated to make suitable bricks and insulation. “The ultimate goal,” says Maurer, “is to reduce the embodied carbon footprint, to be able to make new buildings entirely out of old ones.”

Redhouse Studio is working on a project in Cleveland’s bustling Ohio City neighbourhood that will serve as a prototype of biocycling and showcase the possibilities of sustainable architecture. Maurer and his team are currently renovating a three-storey 19th-century building on West 25th Street to create a boutique hotel. The debris from the hotel will then be “recycled” onsite and combined with organic materials like mycelium to construct the building blocks for a shed at a nearby urban farm.

Facebook Twitter Pinterest A biobrick created using broken down construction waste combined with biobinders made of fungi, plant material and microbes. Photograph: Redhouse Studio

The process of biocycling avoids the high financial and environmental costs often associated with construction. In the US alone, over 500 million tons of construction waste go to landfills each year. Meanwhile, buildings are responsible for nearly 40% of carbon emissions in the country. Biocycling, Maurer says, could reduce the embodied carbon footprint of a construction project, helping to address the changes wrought by global warming even as it cuts costs.

Moreover, Maurer says, mushrooms can be used as a tool in mycoremediation, the use of fungi to degrade and sequester pollutants. Mycologists use mycoremediation to clean up waste sites and contaminated waterways. Because mushrooms can absorb contaminants and toxins such as lead , runs the argument, they’re ideal for converting construction waste to useful building materials.

Mycoremediation is particularly relevant for cities like Cleveland, where children are exposed to lead at around four times the national average and the city’s air quality is ninth worst in the nation, according to a report from the American Lung Association.

The detoxifying properties of mushrooms are also one of the reasons that biocycling “could be especially useful in disaster areas or crisis situations”, says Maurer, and could be used to build sustainable bioshelters for populations displaced by natural disasters – a crucial intervention given that in the US, climate-related disasters killed at least 362 people and cost $306bn in 2017.

Facebook Twitter Pinterest The Hulett hotel, Cleveland, which Redhouse are currently building using the biocycling process. Illustration: Redhouse Studio

Maurer and his team believe the benefits of biocycling in Cleveland could serve as a model for other cities, depending on the climate, the organic materials on hand, and specific local needs.

Still, the effort to make biocycling a scaleable and profitable venture is a daunting one. Some of the barriers to overcome along the way include potential pushback from material manufacturers, as well as scepticism and a possible lack of acceptance in the building industry and from the public.

Epicentre of the Great Recession: what happened to Cleveland's Slavic Village? Read more

Proving that biocycling is both safe and sustainable – and thus bringing buildings built with these new materials up to code – will take time, funding, education and long-term testing. And, adds Maurer, when it comes to biocycling, his team are asking a lot: namely, a paradigm shift in how people view construction materials.

“This work is hard,” admits Maurer. “We’re asking our collaborators to be farmers, architects, engineers, and biologists, and we’re asking microorganisms to help us build. It’s difficult to get the organisms to grow the way you want. They don’t always do what they’re told.” Even so, he’s confident that with more time and practice, “we will continue to develop symbiosis with our little friends” in order to find more innovative ways to build sustainably.

Indeed, mycelium could soon be used to build sustainable technology, which Redhouse is currently discussing with MIT and the University of Akron, and even structures on the moon, about which Maurer says he’s currently in conversation with Nasa.

“So – Cleveland, then the moon,” Maurer laughs. “But first, we’re focusing on Cleveland.”

Follow Guardian Cities on Twitter, Facebook and Instagram to join the discussion, and explore our archive here