Waste that is resourceful: new building materials that regenerate
Marketing Communication
Pictet Asset Management at the Klosters Forum
Hemp, seaweed or even demolition waste?
The Klosters Forum participants, representing a diverse group of building industry practitioners such as architects, engineers, entrepreneurs, insurers and investors, explored ambitious ideas on how to source and introduce nature-based building materials.
In a workshop on “the quest for new building materials & the role of nature”, participants heard from Dr. Merlin Sheldrake, a British biologist, who championed fungi as a valid and practical alternative building material.
The author of the book “Entangled Life: how fungi make our worlds, change our minds and shape our futures” explained why the building industry should tap fungi to benefit from their unique abilities such as carbon absorption and improving biodiversity.
Fungi are “non-human intelligence” which could help humans solve their pressing environmental problems, Sheldrake said.
Fungi indeed are an up-and-coming material in various industries. Engineers have turned mycelium, a complex network of durable fibres that support fungi, into a bioregenerative material that can be used as building blocks.
MycoWorks, a San Francisco-based mycelium start-up, has discovered that its patented bricks made of fungi are sturdy yet flexible, resilient and weather-proof that can be shaped like a cement block. Mycelium-based bricks are compostable with a consistency that is stronger than concrete when compared pound for pound.
Did you know?
The rate of carbon storage in coastal marine habitats (such as mangroves, seagrass and kelp) is around 50x the rate observed in tropical forests
Source: the Management of Natural Coastal Carbon Sinks, IUCN, 2009
Going for “brown gold”
Dr Gnanli Landrou, co-founder of Swiss-based Oxara, used the forum to showcase the cement-free admixture technology that his start-up has developed. Oxara’s patented method mixes clay-based excavation waste with a mineral additive, which hardens after 24 hours, ready to be used in building floors and non-load-bearing walls.
Oxara’s earth concrete has all the processing advantages of the conventional counterpart but emits 20 times less embodied carbon and is cheaper, which means it can help build affordable housing.
That could be crucial.
Data from EU shows construction and demolition waste is the bloc’s single largest waste stream by mass – 15 per cent of which goes directly to landfill 1 .
“There’s plenty of waste that can be recycled. It’s also a financial issue for a company -- if you don’t recycle you have to deal with it,” said Dr Landrou.
“What was considered as waste yesterday is now a resource. In the circular economy there’s no waste. Demolition waste in construction, in the future I hope, will be brown gold. We need to change the construction industry one building at a time.”
– Dr Gnanli Landrou, co-founder of Oxara
Ditte Lysgaard Vind, a renowned circular economy specialist, gave forum attendees samples of building materials made from recycled beer kegs and sea plants. She explained that hemp was another natural material that could be used in construction.
“We can design the world of tomorrow with the waste of today, while designing a world without waste,” she told the forum.
“As we move further into bioengineering, we can turn nature into biomaterials that are convenient to scale.”
The other material Lysgaard Vind demonstrated was made of eelgrass, a plant species found in estuaries, bays and other shallow nearshore areas.
Eelgrass, which absorbs three times more greenhouse gas than trees, is a carbon-negative building material that is also fireproof, rot resistant and a good insulator. It can also be thatched – using a traditional Viking method -- and prefabricated into convenient panels that install easily onto roofs and façades.
While alternative building materials are promising, their commercialisation has been slow in an industry that is typically resistant to technological change.
However, Lysgaard Vind believes changing business dynamics between developers and climate-conscious investors could prove transformative.
Developers – both big and small - have no choice but to incorporate sustainability to avoid the risk of their buildings becoming a stranded asset, Lysgaard Vind added.
“The built environment has become such an asset class that it is servicing the financial industry by offering investment opportunities,” she says. “With investors being the key decision makers, demand for sustainability and transparency is a positive driver now.”
[1] European Environmental Agency
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