The challenges of the industrial sector responsible for a third of the world's waste

Every year, we crush, pull and extract around 100 billion tonnes of raw materials from the fabric of the planet. That amount is equivalent to destroying two-thirds of the mass of Mount Everest every 12 months.

About half of the raw materials we extract go to the construction industry, which generates roughly a third of all the waste on the planet and at least 40% of global carbon dioxide emissions. Compare that figure with the 2-3% caused by aviation, which stirs up far more concern among people.

The “waste” from the consumption of these raw materials is discarded in such immense quantities that its environmental footprint has helped create a new era, which has been named the “Anthropocene”.

The archaeologists of the future will dig through layers of rubble to understand how we lived.

But the material we use and discard today also holds an enormous treasure that could be put to our benefit.

It is estimated that a tonne of mobile phones contains 300 times more gold than a tonne of the highest-grade gold ore, as well as significant amounts of silver, platinum, palladium and rare metals – while we keep tearing up the earth with continuous mining to obtain more of these materials.

The vast quantities of copper available in billions of cables around the world are a reusable source of metal with a much higher concentration than the less than 1% found in top-grade ores.

All of this raises an obvious question: why don't we reuse what we have already extracted, instead of digging up the planet in search of ever more raw materials?

This thinking has been prompting a growing group of architects and construction companies to examine how to reuse the immense amount of materials hidden in the environments we have already built, from concrete and timber to the metallic riches of electronic waste.

In 2005, the architecture firm Superuse, based in Rotterdam, the Netherlands, set an innovative milestone for a new vision of construction by creating Villa Welpeloo – the world's first contemporary house made mainly from construction waste materials.

Steel from old textile machines and timber from damaged industrial cable reels make up 60% of the second-hand materials used in the building.

Later, in 2013, British architect Duncan Baker-Brown went beyond Superuse by using more than 90% waste materials to build the Brighton Waste House in England.

Baker-Brown combined many different materials, from used denim to plastic DVD cases and discarded toothbrushes, to make up the wall insulation, as well as old bicycle inner tubes to insulate the floor against sound and impact.

Around 10 tonnes of chalky soil destined for landfill were collected to create rammed-earth walls, and used carpet tiles from an office provided the exterior cladding.

“The waste house is a ‘live’ research project that makes people think about where these materials come from and where they end up,” says Baker-Brown.

He set out a model for a new way of building with minimal waste in his 2017 book The Re-Use Atlas, which teaches its principles to a growing generation of architects and builders at the University of Brighton's school of architecture.

He offers a simple and powerful redefinition of waste as “just useful stuff in the wrong place”.

Although these ideas fall under the “circular economy” umbrella, Baker-Brown uses a more striking expression: he stresses the need to “mine the Anthropocene” instead of digging up new materials.

“We need to become ‘urban miners’ and rework [or] reuse buildings, components and material sources that are already available,” he wrote in a rallying call to action published in the journal of the Royal Institute of British Architects in 2019.

Baker-Brown is currently finishing a pavilion for the world-renowned Glyndebourne Opera in Sussex, UK.

The pavilion is being built from waste products including oyster shells, champagne corks and rejected under-fired bricks from a nearby brickworks.

Crucially, he is also using these materials in a way that makes them easy to deconstruct later – joining elements with nails instead of glue, for example – to create what he calls “a materials store for the future”.

The idea of designing buildings specifically with reuse in mind has earned the label “design for deconstruction”.

The 2012 Olympic Games showed these ideas in action with the construction of temporary accommodation for 17,000 athletes in London.

To this end, the buildings were designed so that they could later be remodeled into sustainable homes for local residents, thanks to elements such as partition walls on each floor that can easily be moved to form new layouts.

But those willing to mine the Anthropocene mostly have to work with existing buildings that were not designed for deconstruction or reconstruction.

The Dutch firm Maurer United Architects took on this challenge by building 125 new social housing units with more than 90% materials recycled from old apartment blocks in the Superlocal Estate development in the city of Kerkrade, the Netherlands.

Huge sections of concrete flooring were cut out and lifted from the old buildings and set down to provide the frames of the new homes, while the remaining concrete was crushed on site for reuse, in an approach that the firm's founder, Mark Maurer, calls “smart demolition”.

One key to successfully mining the Anthropocene for our future buildings is devising ways to reuse existing materials in a multitude of forms.

Folke Köbberling, professor of architecture-related art at the Technical University of Braunschweig, Germany, has spent years perfecting ways to reuse materials.

“Using recycled material is different from working with new materials,” she says. “These materials have a history. We seek out the materials and try to use them as they come, in a very flexible way.”

One example is the amphitheater that she and her colleague Martin Kaltwasser built in 2008 at the Wysing Arts Centre, near Cambridge, UK.

Made mainly from 400 wooden pallets salvaged from local building sites, it also includes windows from old greenhouses and teak flooring recycled from shelving discarded by the University of Cambridge.

With a total cost of just 5,000 euros (R$ 30,700), the structure was conceived to provide a distinctive space for the arts for two years, before being dismantled so its materials could be reused elsewhere. But it is still serving very well.

Köbberling also discovered that discarded raw sheep's wool makes an excellent pollution filter and wall insulation, and she even turned thousands of plastic bottles and cups discarded at the Berlin Marathon into roofing material for bus shelters.

Connecting the source of these materials with the demand for components is a key element in the effort to reinvent waste as a new building material.

“We need to find a way to create prosperity and added value, not by producing new goods, but by maintaining and managing existing goods,” says Michael Ghyoot, co-founder of the design firm Rotor, based in Brussels, Belgium – which is focusing its efforts on making reuse easier for construction professionals.

Rotor has teamed up with other European companies in a project funded by the European Union to build an online directory that has already brought together just over 1,000 dealers specializing in material salvage and related businesses (the pandemic hampered the original goal of bringing together 1,500 participants).

It is also creating a pre-demolition toolkit to help companies determine the reuse potential of materials and products in buildings slated for demolition or refurbishment.

The remodeling of the 59-story Montparnasse Tower by the architecture firm Bellastock, based in Paris, France, is another example of mining the Anthropocene in action.

The architects used concrete, glass and steel from the building's façade and interior to help create new levels and spaces, without resorting to demolition waste.

The transformed tower is scheduled to be ready in time to welcome visitors for the Paris 2024 Olympic Games.

Mathilde Billet, technical director of reuse at Bellastock and project manager for the de/reconstruction of the Montparnasse Tower, argues that entrenched behaviors in the construction sector, rather than practical barriers, are the main obstacle to the widespread implementation of the principle of reuse.

“The hardest part is changing the way we think,” she says, adding that greater awareness, training, conferences and simply talking can remove much of this fear of change.

“We need to imagine the city as a materials bank, ripe for reuse. There are no major changes involved. It just takes a little willpower and agility,” she says.

Michael Ghyoot also points out that the process of making existing materials ready for reuse creates a range of new jobs.

“This activity is labor-intensive: [it requires actions such as] cleaning the edges of a marble slab, removing cement from tiles, replacing the wiring of old electrical appliances – and documenting all the materials,” he says.

For Mathilde Billet, the principles underpinning the mining of the Anthropocene are also in harmony with age-old practices, whether the reuse of stones from old buildings, which was common for centuries, or the constant rebuilding of large clay structures in countries such as Mali.

“Reuse requires old technology,” she says. “This technology exists almost everywhere on the planet, but it is slowly dying out.” The alarming situation we find ourselves in means we need to return to a more frugal architecture, she says: “an architecture built with the material of the place where it stands”.

Far from being completely at odds with practical economics, a 2020 analysis of five European Union countries by the Club of Rome concluded that shifting to a more circular economy would cut their carbon emissions by two-thirds and create more than one million new jobs.

What really makes little economic or environmental sense is to keep digging billions of tonnes of new raw materials out of the planet.

Source: https://www.bbc.com/portuguese/internacional-60076040?at_medium=RSS&at_campaign=KARANGA

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