Sustainable building materials can come from sources you won’t believe, like seaweed, mushrooms, and even coffee!
When we think of building sites today, concrete, glass, and steel are the three materials that most often come to mind; but did you know there are plenty of alternative, more eco-friendly building materials that can actually replace the most common ones? These sustainable materials come from sources like seaweed, mushrooms and even coffee husks, allowing designers and engineers to construct green buildings with a low carbon footprint.
So what does being a sustainable building material entail? Fortunately, eco-savvy manufacturers have begun to create materials that are more energy efficient, come from natural sources, or are recycled from waste materials for construction.
Let’s take a look at some of them and their practical applications in eco-friendly constructions:
1. Cork
Formerly used solely as wine stoppers or bulletin boards, in recent years, cork has been found to be one of the most sustainable building materials in the world!
With eco-minded construction companies in search of more lightweight, low cost, sustainable, and versatile green building materials that not only are aesthetically pleasing, but also effectively insulate and provide long-term protection from the elements, cork ticks all the boxes.
Cork is harvested from a water-repellent layer of bark on the cork oak tree, mostly grown in the Mediterranean region of Southwest Europe and Northern Africa.
One reason that cork is so sustainable is that no trees actually need to be cut down in order for it to be harvested, and it is easy to recycle.
The trees grow for 25 years until their trunks are wide enough, and the cork can be stripped from them every nine years. Cork oak trees can live up to 300 years, and the older a cork tree is, the better quality the cork that is harvested is too.
Cork is fire-retardant, buoyant, elastic, and impermeable. This makes it ideal to be used in the production of temperature and sound insulation indoors, but also as the infrastructure for homes and buildings. Interconnecting blocks and roof tiles made from cork can provide durability and easy assembly, while also allowing the structure to blend in with its surrounding environment. Below are just a few examples of how cork has been used in building green homes, hotels, studios, and exhibitions around the world.
2. Coffee Husk Low-Cost Housing
Colombia is one of the world’s largest coffee producers, exporting an estimated 15 million bags of coffee beans in 2019 alone.
Despite this booming business, Columbia is also unfortunately one of the world’s most economically disadvantaged countries, with around 35% of its population living in poverty. This has led to many people unable to afford housing, an issue that Bogota-based construction company, Woodpecker, hopes to solve.
By combining coffee husks with recycled plastic, Woodpecker has developed building blocks that link together around a steel frame to create lightweight and easy to install tiny homes that can serve as single family homes or classrooms for rural or more isolated areas.
The coffee husk is the skin of the coffee bean that dries and falls off during the roasting process, and usually ends up in landfills afterwards.
It is stronger and drier than other fibres, and allows for these homes--which sell for less than $5,000 each--to be pest- and moisture-resistant. Nearly 3,000 of Woodpecker’s eco-friendly buildings have already been sold, and the company is working with the Colombian government to help house those who have been displaced due to natural disasters.
3. Newspaper Wood
For projects inside the home, Dutch designer Mieke Meijer, and her team at Vij5 have developed NewspaperWood, an original material adaptable for floorboards, hybrid furniture, shelving, concept car interiors, and more. Made from sheets of recycled newspaper glued together and layered, the pieces are then dried, compacted, sawed and sanded, giving it the look of wood grain.
Due to the size and strength limitations of newspaper, NewspaperWood is not aiming to act as a large-scale alternative to wood, but it does offer a potentially greener solution to the global paper waste problem. In the UK alone, it is estimated that over 6.3 trillion tonnes of paper are thrown away every year, whereas recycling can save millions of trees.
4. Mycelium
Imagine an eco material with the potential to be the key to a sustainable future in the fields of fashion, art, food, shipping, green construction, and more. Mycelium, or the tiny thread-like roots of mushrooms, may just be able to fill these big shoes. It is 100% biodegradable and compostable, yet when dried it is strong and durable enough to resist mould, water, and fire.
In recent years, Mycelium has been used for creating eco-conscious packing materials, meat alternatives, and even skincare products. Now, however, mycelium compressed into bricks is one of the construction industry’s most exciting and promising new building materials.
Because fungi are living, breathing organisms, they self-regenerate quickly, and can assemble themselves into lightweight, yet solid objects in a very short time. For more precise, or complex projects like insulation, Mycelium can be used in 3-D printing, too.
Examples of Mycelium structures include:
The Growing Pavillion in the Netherlands created to showcase how mycelium self-assembles
The MycoTree project in Seoul, South Korea - exhibited to show how mycelium is strong enough to act as essential structure and support for buildings, while also adding natural beauty to any space.
5. Green Algae Building
You may think of green algae as something that only grows in your local pond or river, but in Hamburg Germany, green algae is being used to provide energy for an entire building. At the B.I.Q. (Bio Intelligent Quotient) building, the photosynthesis occurring in the algae’s cells turns the sun’s energy into fuel.
The algae rapidly grows within the glass panels that cover the entire building, and then is extracted and put into a bio-convertor which turns the algae into biomass. This biomass can then be used for a number of things including a source of food for humans or animals and it can also ,power cars, but its greatest ability is that it can generate electricity and heat for those living in the building.
When we visited this project in 2019, we were told that the process was producing so much energy that it could also power the surrounding buildings too, making it a fantastic eco-material. You can learn more about this and other green projects in our Green Architecture Video!
6. Knowaste
In the UK alone, nearly 3 billion disposable diapers are thrown into landfills each year. To tackle this issue, Canadian company, Knowaste, are recycling diapers and other absorbent sanitary products into sustainable roof tile materials!
The recycling process sanitises the waste to create two different materials: first, they remove the organic fibres and use them for green energy and paper, while the plastic binding from these sanitary products is then extracted to be recycled into a variety of products, including plastic cladding, decking and roof tiles.
Sending these otherwise disposable products to the Knowaste facility will save the same amount of space in the UK’s landfills as 96 olympic sized swimming pools and remove from the air the same amount of carbon dioxide as 7,500 cars. Not to mention that once they’ve been processed, they turn into a much-needed eco building material.
7. Cob
Cob is a mixture of sandy soil, clay and straw. It is mixed by crushing the particles together by either dancing on it (yep, dancing!) or using a digger. It is an extremely cheap and eco-friendly building method, for example, the Cob Cottage in Canada was constructed for just £3000.
It is one of the most eco-friendly materials of all the examples mentioned in this video, as the materials for construction can be found on the site of construction rather than needing to be imported from elsewhere.
It is also in my opinion the best looking material, as cob allows you to easily create unique home styles, curves, and furniture built directly into the walls.
8. Plastic bricks
Kenyan engineer Nzambi Matee discovered that Nairobi’s plastic waste pollution was becoming a serious problem. Nairobi produces over 500 metric tonnes of plastic waste every single day….but less than 9% of the city’s plastic waste was being recycled; and instead of waiting for the government to do something, Matee took action.
Machines that Matee designed herself mix plastic and sand together at high temperatures where the plastic, when melted, acts as a binder. The mixture is then compressed into bricks that are stronger than concrete and lighter too, which helps cut costs in shipping, and makes their use in building less labour intensive.
Looking toward the future, there is no limit to what Matee hopes to achieve. Seeking investors across Africa to scale her business for the whole continent, Matee hopes to pave the way for upcycling efforts around the world.
9. Plant-based foam
Plant-based Polyurethane Rigid Foam is manufactured from materials like kelp, hemp, and bamboo and can be used in insulation and furniture. It is highly resistant to moisture and heat and offers protection against mould and pests.
Usually, vegetable-based foam insulation comes in two forms: soybean insulation and castor insulation. In addition to being considered more eco-friendly, some types of plant-based foam have actually been shown to improve insulation, thermal resistance, and act as better protection against issues that often plague homes using typical insulation materials.
10. Seaweed house
On the island of Læsø, located off the coast of Denmark, homes made with roofs of seaweed dot the landscape--some of which are more than 300 years old. These roofs can be up to a metre thick, and the way they hang over the walls gives the house the appearance of wearing a cloak.
Apart from their humongous size, they look a lot like thatch, but seaweed is far more durable, as it reproduces itself every year in the sea, and comes ashore without any effort from humans. It is then dried on nearby fields by sun and wind, and is easily carried to building sites due to its light weight.
A more modern example of seaweed used in building materials that are environmentally friendly are seaweed pillows which were used as cladding for an eco-friendly house designed by the Copenhagen architecture firm Vandkunsten. Their aim was to design a new house that combines the traditional material with twenty-first century construction techniques.
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