9 building materials made entirely from waste products

No doubt an architectural treasure trove. Image: Cezary p at Wikimedia Commons.

Building with Waste, a new book about, well, you can guess, may not sound like it should top your holiday reading list – but, construction geeks as we are, we found its premise fascinating. Every year, human settlements produce 1.3bn tonnes worth of solid waste products. The book argues that we could and should be putting this to good use as cheap, durable and green building materials. 


Compilers Dirk E. Hebel, Marta H. Wisniewska and Felix Heise looked into the worlds of architecture, construction, and the delightfully named field of "garbology" to find new and exciting materials made out of stuff you'd normally find at a landfill site. Their book argues that, in future, we could end up re-using pretty much everything, as we did back when all waste was organic.

This could come in handy if, as is predicted, our municipal waste output doubles by 2025. As Mitchell Joachim, one of the book's contributors, puts it:

The future city makes no distinction between waste and supply. 

So, from animal blood bricks to nappy roofing, here are our favourite waste-based materials featured in the book. 

1. NewspaperWood

Image: ViJ5.

This design comes froom Norway, where over 1m tonnes of paper and cardboard are recycled every year. The wood is created by rolling up paper and solvent-free glue to create something not dissimilar to a log, then chopping it into usable planks. The wood can then be sealed so it's waterproof and flame-retardant, and used to build anything you would normally build with wood. 

2. Nappy roofing

Image: Lightweight tiles ltd.

Good news: something can be salvaged from all those nappies and sanitary products we throw away, even though they're, well, really gross. Special recycling plants separate out the polymers from the, er, organic waste, and these polymers can then be used to ceate fibre-based construction materials like the tiles in the image above. 

3. Recy blocks

Image: Gert de Mulder. 

These colourful bricks are made from old plastic bags, which are notoriously difficult to recycle in any other way. Recycled bags or plastic packaging are placed in a heat mold, and forced together to form the blocks. They're too lightweight to act as load-bearing walls, but can be used to divide up rooms or outdoor areas. 

4. Blood Brick

Image: Jack Munro.

This idea rests on the assumption that animal blood counts as a waste product. This, we realise, is a potentially offensive idea – but while carnivores are still munching away, they're still wasting loads of animal blood, especially in societies without industrialised food production systems. And, as it turns out, blood is one of the strongest bio-adhesives out there, as it contains high levels of protein. 

British architecture student Jack Munro proposes using freeze-dried blood (which comes as a a powder), mixed with sand to form a paste; this can then be cast as bricks. This could be especially useful in remote communities, where blood from animal slaughter is plentiful, but strong construction materials are thin on the ground.

5. Bottle bricks 

Image: Aaron "tango" Tang via Flickr. 

This proposal is a little different, as it relies on producing a consumer good specifically so it can later be used as a building material. Lots of companies now make bottles in cuboid or other tesselative shapes, to make them easier to transport.

But the practice of doing so to create construction materials actually started with beer company Heineken in the 1960s – Alfred Henry Heineken, owner of the brewery, visited a Carribean island and was dismayed at both lack of shelter, and the number of discarded Heineken bottles scattered everywhere. So the company landed on a new, brick-shaped design for the bottle, shown in the images above. The bottleneck slots into the base of the next bottle, forming an interlocking line. 

6. Smog insulators

Image: New Terrirories/City of Bangkok.

One of our biggest waste receptacles is the air, which isn't great for our lungs, or for the human race's chances of survival on a planet that's rapidly getting hotter. "Dustyrelief", a system created by the City of Bangkok and design firm New-Territories, involves placing an electrically charged metal mesh over a building, which attracts large smog particles and sticks them together. Eventually, this creates a kind of silvery fur over the building's surface. Not particularly attractive, perhaps, but much better than a similar shag forming on the insides of your lungs.

7. Mushroom walls

Image: Evocative designs.

Here, designers figured out a way to grow wall insulator and packing materials using mycelium, a bacteria found in rotting organisms like tree trunks and agricultural byproducts. If placed in a mold, these organic matters grow to the desired shape within a couple of days, and can then be stopped using a hot oven. This is particularly useful because traditional insulating and packing materials tend to be non-biodegradable, or, in the case of asbestos, poisonous.

8. Plasphalt 

The bit on the left is plasphalt, the bit on the right is asphalt. Image: TEWA.

OK, yes, we mostly like this one for its fun name. Plasphalt is made up of grains of plastic produced from unsorted plastic waste, which replaces the sand and gravel traditionally used in asphalt production. In testing, it was found that plasphalt roads were far less vulnerable to wear and tear than traditional asphalt, because the asphalt emulsion bonded better with the plastic than with gravel or sand.

9. Wine cork panels

Image: Yemm & Hart materials.

These wall or floor tiles are made by combining recycled granulated cork with whole wine corks, which you can see as those oblong shapes in the tiles above. This is a pretty useful idea, considering the world apparently consumes around 31.7bn bottles of wine a year. For shame.

 
 
 
 

Wild boar are moving back to Genoa, and not everyone is pleased

A wild boar, c1933. Image: Getty.

Crossing the Ponte Gerolamo Serra in the Italian city of Genoa, I spotted a small crowd clustered by the river wall. I approached, intrigued, and peered over the wall to discover the subject of their delight: a sounder of eight wild boars – the adults sheltering from the heat in the undergrowth, while the juveniles foraged among the foliage that grows in the river bed during the dry summer months.

In any other city, such a sight might have been surprising. But in Italy, and particularly in the region of Liguria, where Genoa is located, the population of wild boars has been increasing at such a rapid rate that these incidents are now common. Across the country, it’s estimated that the population has risen from 600,000 to 1m over the past decade.

But while wild boars may look comically out of place trotting about the city, it’s actually a natural result of the way people have migrated – and the wars they have fought – over the course of recent history.

Making a comeback

A species native to Europe, the wild boar (or “cinghiale”, in Italian) largely disappeared from its historical territories during the 18th and 19th centuries. Their decline was widely attributed to the combined effects of habitat change, competition for space and resources and, of course, hunting.

Wild boars were a prized quarry, revered for their ferocity – and the danger involved in pursuing them. According to local folklore from the region of Liguria, the last truly wild boar was hunted and killed in 1814, in the province of Savona.

After an absence of more than a century, wild boar began to return to Liguria, and to the neighbouring region of Piedmont. A further influx occurred during World War I, when it’s believed that military activities in the south-east of France forced parts of the population back into Italy over the Alps.

Although hunting fraternities were quick to augment this fledgling population with wild boars transported from elsewhere, the return of the species was primarily due to natural causes. From the 1950s onwards, traditional agricultural practices were abandoned as more and more people moved from rural towns into the cities. This meant that large areas of formerly cultivated terraces and pastures were rapidly overgrown, fast becoming dense secondary woodlands.

A city gone wild

This spontaneous “rewilding” has become a controversial issue in the region. Many conservationists and environmental organisations consider the region’s return to a “wild state” a success. But others believe that the encroaching wilderness signals a loss of traditional woodland knowledge and a reduction of biodiversity, associated with the pastures and meadows.


The province of Genoa is among the areas most densely populated by wild boar in Italy, with an estimated 25 boar per 10km². Rewilding processes have brought woodlands to the city limits, blurring the boundary between rural and urban areas. The species has expanded beyond the hinterlands, colonising highly urbanised, densely populated city spaces in Genoa, drawn by the abundance of food waste created by humans.

In 2009, the infamous boar Pierino made his home at Righi, on the outskirts of Genoa, where he was routinely fed with focaccia by enthusiasts. Today, a family of wild boar call the Albergo dei Poveri – a historical hostel for the Genoese poor in the city centre – their home.

But while their antics are often recorded and shared with glee on social media, the threats posed by the presence of wild animals has become a preoccupation for the city’s municipal administration.

Boorish behaviour

Wild boar have been involved in a number of traffic accidents, and have proven to be particularly dangerous when with their young, attacking dogs and even people. The city council in Genoa has put forward many proposals to reduce the number of animals in the city, ranging from forced removals, to sterilisation, increased attention to waste disposal and approved hunts. About 90 wild boar were reportedly culled in 2018.

Needless to say, each of these measures has been hotly debated. Animal advocacy groups staunchly oppose the proposals, and sometimes obstruct the authorities’ attempts to take action, often sending patrols to care for the animals, and even give them names. But other residents are displeased with the animals’ presence in the city, and have consulted with the council on how to address the problems that they cause.

And so Genoa continues to grapple with thorny issues surrounding the presence of wild boar in the city, with the city authorities seeking to resolve a polemical issue that embroils the lives of animals and humans alike. So far, a collective, coherent and communally agreeable strategy has proven evasive; one that considers the need for public safety, hygiene and health with the ethical responsibilities towards to wild boar themselves.

Meanwhile, the animals themselves continue to lounge and forage beneath the Ponte Gerolamo Serra and elsewhere, bringing a little of the wilderness into the city.

The Conversation

Robert Hearn, Assistant Professor in Human Geography, University of Nottingham.

This article is republished from The Conversation under a Creative Commons license. Read the original article.