The Natural Revolution

Crafting Earth-Friendly Materials and Techniques
Written by Karen Hawthorne

We’re not expecting the internet to suddenly go dark or electricity to fail – but there’s certainly a growing interest in living more self-sufficiently. People are planting vegetable gardens, using bamboo flooring and buying solar roof shingles to generate power.

Maybe it’s the impact of the pandemic, making you realize you can’t take it all for granted. Change is constant and we should do what we can to enjoy the moment. And if it makes us better stewards of the planet, that’s a trend worth following.

In the construction industry, we’re seeing changes like requirements for social distancing, more remote technology, 3D printing and supply chain diversification. There’s also a lot of exciting innovation when it comes to environmentally friendly alternatives to conventional methods and products. Even better, many of these support the circular economy by reusing waste from agriculture and manufacturing for construction materials.

The industry is greening for the welfare of the next generation – and for the many commercial and residential clients who see the value in sustainable building.

“Standard building practices use and waste millions of tons of materials each year; green building uses fewer resources and minimizes waste. LEED projects are responsible for diverting more than 80 million tons of waste from landfills, and by 2030, that number is expected to grow to 540 million tons,” says the U.S. Green Building Council.

The top two triggers for green building in America? Customer demand and healthier buildings with cleaner indoor air quality and comfortable, consistent heating throughout. But the economic benefits also deserve a second glance. The operating cost savings and higher asset value in new green buildings and green retrofits have been well documented in the World Green Building Trends’ SmartMarket reports.

In terms of the comfort consumers are seeking, builders are focusing on geothermal techniques for heating and cooling, including the use of traditional rammed earth walls and floors. They are dramatic and durable, offering thermal storage for the sun to warm them and then slowly releasing that warmth in the cooler evening.

There has also been a renewed interest in using straw bales produced from waste from the agricultural industry for walls and insulation. The first documented use was for a 1896 Nebraska schoolhouse, says the International Association of Certified Home Inspectors, so it’s a time-tested practice. Straworks, a Canadian design and build company based in Peterborough, Ontario, has specialized in straw bale construction since 2004, building homes for minimalists who want to reduce their carbon footprint or live off the grid entirely.

Consider that instead of burning the thick and durable straw to get farm fields ready for the next harvest, straw bales could become an essential part of the transition to natural building alternatives.

In the same vein, we need to take a look at mushrooms. Not the kind you’ll top your next pizza with, but mycelium, the vast network of fungi living underground. This is the mushroom root, while its flowers are the mushrooms themselves that you can forage and cook with (if you know what you’re doing).

One of the most promising construction trends on the horizon is the development of living materials like bacteria and fungi. It turns out, the mushroom root is a wondrous renewable resource that could transform the construction industry. In fact, the largest living organism on earth is a honey fungus in the Blue Mountains in Oregon that’s 2.5 miles across, several thousand years old, and makes delicious mushrooms.

In fact, cockroaches, like the one in the Pixar movie Wall-E, aren’t the only tough creatures that will survive an apocalypse (or the next pandemic variant). Scientists around the globe have harvested different fungi for use in antibiotics and emerging treatments for HIV and the Zika virus. They’ve also fed these organisms farm waste to grow them into all sorts of new materials for the building industry – for flooring, particle board replacement, and insulation, to name a few.

As these robust fungi grow, the mycelium threads branch out like tree roots, but also probe into nooks and crannies in the soil, binding it together. They are like nature’s super glue – which means that they can be used to make products that are stronger than concrete, more insulating than fiberglass, and completely compostable. Because these new materials are built and made of bacteria and fungi, they are also super-light and portable – impressive when you think of all the possibilities for greener building and efficiencies.

Now products and inspiration are coming out of the laboratories and onto the market.

Dell Computers is growing its own mushroom cushions instead of using petroleum-based foam pieces for packing and shipping its high-end gear. The cushions are biodegradable and can be used for mulch in your flowerbed.

Scientists at the Italian Institute of Technology in Genoa, meanwhile, have found they can change the qualities of the new material by altering what it has to digest. “The harder a substance is for the fungi to digest – such as wood chips rather than potato peelings – the stiffer the resulting mycelium material is, for example,” says the BBC in a feature report on the “unexpected magic of mushrooms.”

Indeed, scientific study and intervention can develop fungi for more vigorous purposes. MycoWorks in California, for instance, has fused wood together with mycelium to make bricks that are tougher than conventional concrete and fire-retardant. Traditional bricks rely on fired clay and mortar, a bonding agent of cement, sand and water, depleting precious resources.

Biotechnologists at the Royal Melbourne Institute of Technology in Australia are working on similar fungal brick with rice hulls and crushed waste glass. “They not only provide a cheap and environmentally friendly building material, but they also help to solve another problem facing many homes in Australia and around the world – termites. The silica content of the rice and the glass makes the material less appetising to termites, which cause billions of dollars in damage to homes every year,” the BBC reports.

The Melbourne team is also using the fungi to produce new biostructures and enzymes for sound absorption, strength and flexibility in building materials.

And you thought getting the weather forecast and sports scores on demand from Alexa was cool! Well, fungi can also be used in combination with traditional building materials to create a smart concrete that can heal itself. As the fungi grows into any cracks that form, it secrets fresh calcium carbonate – the key raw material in concrete – to repair the damage, reports the New York Times. The material can also grow into the pores of concrete for superior impermeability.

“Most concrete requires virgin sand from rivers, lakes and oceans, which is running short worldwide, largely because of the enormous demand for concrete,” according to the Times. But the new living material can use waste materials like ground glass or recycled concrete.

Dr. Wil Srubar, head of the living concrete project at the University of Colorado, Boulder, says the tools of synthetic biology could dramatically expand the realm of possibilities. Imagine building materials that light up to reveal structural damage or that can detect toxic chemicals.

And living concrete could be the solution in environments that are harsher than even the driest deserts – on other planets like Mars. “There’s no way we’re going to carry building materials to space,” Dr. Srubar says. “We’ll bring biology with us.”



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