The Most Sustainable Building Materials: We Pick 5 Winners

A picture of a high-rise building with plants growing all over its exterior. The words "The Most Sustainable Building Materials" are at the top and a graphic of the earth in green is overlain at the bottom.

Sustainability is a key concern regarding the construction industry’s future, with the sector looking to use the most sustainable building materials possible.

The continued use of wood, concrete, and fired earth bricks as construction materials is not sustainable for the future due to the destruction of trees and the use of non-renewable natural resources.

As such, there is a need to invest in sustainable building materials, with recycled steel, recycled wood, and even recycled plastic now used for construction purposes to minimize the sector’s environmental impact.

In addition, we are seeing more and more new buildings incorporating renewable energy generation, such as solar panels, and using them alongside more natural materials like sheep wool insulation and hemp fibers.

But what is the most sustainable building material to use these days?

Bamboo is the most sustainable building material. Besides absorbing carbon dioxide from the atmosphere, bamboo can grow up to 2.91 feet per day. This rapid growth rate means bamboo regenerates quickly, reducing the impact of deforestation on the environment.

In the rest of this article, I’ll discuss the five most sustainable and renewable building products ranked from the best to the worst.

This will help you make an informed decision about eco-friendly building materials for your next construction project that will reduce its carbon dioxide emissions and wider environmental impact.

But is it time to ditch the precast concrete in favor of adobe blocks and straw bales?

Let’s find out!

1.  Bamboo

A dense bamboo grove with tightly-packed plants.
Bamboo grows widely in Southeast Asia and India in dense, fast-growing groves. There is an abundant supply of this renewable building material.

Bamboo is first on this list of the most sustainable construction materials for a good reason.

Let’s go back to the definition of sustainable building materials to help you understand the reason behind this ranking.

Sustainable materials can be reproduced in required volumes without depleting natural materials or harming the steady equilibrium of the environment.

Bamboo fits this description because it grows quickly and is a renewable material, making it ideal for construction projects requiring high volumes of raw materials.

Durability is always the elephant in the room when considering bamboo as a sustainable building material. Most people think bamboo is fragile since it belongs to the grass family, but it is very strong and can be used for many applications where recycled steel is currently used.

Bamboo has a high tensile strength, making it durable and a sustainable alternative for construction. With a tensile strength between 140N/mm2 and 280N/mm2, an inch of bamboo can hold up to 7.5 tons of weight while retaining its shape.

Moreover, since bamboo belongs to the grass family, it doesn’t have weak points along its length. Thus, it’s an excellent source of durable plywood.

Compared to concrete or steel, bamboo is a lightweight material that’s less energy-intensive to transport. This makes it an eco-friendly material that helps reduce the carbon footprint of your construction project.

While there are some concerns about using bamboo in construction, such as pests and mold, you can manage these issues by adequately protecting the material from the elements and applying pest-resistant treatments.

Treating bamboo with preservatives like boron is one way to extend its lifespan. Boric acid treatment also makes bamboo slightly more fire-resistant.

The table below shows how long bamboo can last before it needs replacement:

Bamboo SectionUntreated BambooBamboo Treated With BoronBamboo Treated With Fixed Preservatives
Internal2 to 6 yearsMore than 30 yearsMore than 30 years
External above the ground0.5 to 4 years2 to 15 yearsMore than 30 years
External in contact with the groundLess than 0.5 yearsLess than 1 yearMore than 15 years
Table 1: Bamboo’s lifespan

In addition to the sustainable and durable qualities of bamboo, other benefits of using this building material include the following:

●     High thermal insulation: Bamboo has a thermal conductivity of less than 0.082 Wm−1K−1. Such a low thermal conductivity rate means it’s an excellent insulation material that will help you save on energy bills due to the reduced heating energy requirement.

●     High resistance to earthquakes: Since force is the product of mass and acceleration, lighter materials generate less force. Being a lightweight material, bamboo has a lower force production and, combined with its structural strength, is thus resistant to earthquakes.

●     Flexibility: Unlike concrete, bamboo maintains flexibility even when exposed to high stress. This makes it ideal for use in construction projects that entail extreme loads.

For more information about bamboo homes, including how much they cost, please read our bamboo homes article here.

2.  Cork

A cork oak tree with bark stripped after harvesting.
Cork can be harvested from the cork oak tree about once every nine years.

Cork is the second-best of the eco-friendly construction materials on our list due to its rapid growth.

The process of harvesting cork is sustainable and requires cutting the tree bark from the oak tree, which is a much more eco-friendly alternative to cutting down the whole tree for lumber.

Once removed, the tree continues growing and can live for around 250 years.

Cork is a highly resilient and flexible material, making it ideal for use in the building sector. Its flexibility allows it to revert to its original shape after sustaining pressure. As a result, it makes an excellent material for floor tiles.

Like bamboo, cork is a lightweight, natural material that causes minimal strain on the earth’s resources.

After harvesting, you can easily transport the cork tree bark to your construction site without using too much energy. This significantly reduces the carbon footprint of your project since fuel consumption is limited.

Finally, cork can be your go-to material if you live in an extremely cold area.

Since cork is a good thermal insulation material and imperishable and impermeable to gas and liquid, it maintains the temperature of a building, even in extremely cold temperatures, without rotting.

These excellent insulation properties help to improve your home’s energy efficiency and lower its energy costs. This will, in turn, reduce carbon dioxide emissions, mitigating its contribution to global climate change.

The table below shows the properties that make cork a structurally sound construction material:

Density400-1,500kg/m3Less environmental impact
High durability
More sustainable
Compressive strength1-26 MPaAble to withstand heavy loads
Able to resist stress due to weather elements
Flexural strength0.5-4.0 MPaEnhanced longevity
High end-user safety
Table 2: Structural properties of cork

3.  Adobe

A stack of adobe blocks ready for building with.
Adobe blocks are a very sustainable building material with super low embodied energy and uses natural materials in production.

Don’t worry if this is your first time hearing about adobe; most people are unaware of this material.

Adobe is a sustainable building material that has been in use in some parts of the world for centuries and is a more sustainable alternative to traditional concrete blocks or fired bricks.

Usually, adobe is made by mixing water, earth, straw, and dung (this may sound a bit gross). However, these ingredients are environmentally friendly and sustainable as they don’t deplete natural resources.

Adobe’s manufacturing process, use, lifespan, and disposal result in near net-zero carbon emissions. As already mentioned, all the ingredients you need to make adobe are readily available and natural.

Adobe doesn’t disappoint when it comes to structural flexibility. It’s a versatile material that can be molded into different shapes and sizes. Therefore, it’s ideal for diverse projects, including stables, floors, and walls.

What’s more, adobe is remarkably resilient. It maintains its shape and strength after long exposure to the elements.

It’s also a lightweight material that can be easily transported, which makes it an excellent choice for building in areas with poor or nonexistent infrastructure.

Its thermal mass means that it absorbs heat during the heat of the day in the summer and warmer temperatures, slowly releasing it at night when it is cooler, thereby evening out the temperature in the house.

It’s worth mentioning that excessive exposure to water and high humidity can break adobe bricks. Therefore, advanced modification is necessary if you live in an area with high humidity and a rainy climate.

If this is your case, you must combine adobe bricks with rammed earth or other stabilizers. The El Encuentro project in Bogota is one example where this approach was useful in constructing a durable house.

The only downside to adobe is that some people may find it gross (especially the use of dung). However, it’s worth it if you want a sustainable, environmentally friendly, and durable building material.

Here is a video illustrating how to make adobe:

Video thumbnail of people removing a wooden mold from adobe bricks.
YouTube Video: How to Make Adobe.

4.  Mycelium

A hand picking a fruiting body of fungi with the mycelium visible in the soil substrate.
Mycelium can be grown into blocks that lend themselves to building walls and other structures.

Although building a house with a fungus may seem odd, mycelium is an excellent and sustainable material for construction.

Mycelium is the root-like part of a fungus that grows underground. This makes it a sustainable and renewable building material since it doesn’t require cutting trees during its harvest.

Mycelium is highly durable and resistant to elements like water, fire, and mold when dried.

Due to its organic and compostable nature, mycelium is an eco-friendly material that doesn’t put pressure on the environment.

It leaves little waste, which means a reduction in environmental pollution. It can even use recycled plastic bags as food, solving another environmental problem.

Moreover, its high resistance to the elements when dry makes it excellent for many construction projects. You can use it for insulation, roofing, building, and flooring.

One main concern with mycelium is that it could be more durable for construction than other eco-friendly materials.

However, you can mitigate this drawback by combining it with other recycled materials like sawdust, demolition waste, and timber. This way, you’ll get a stronger building material to mold into bricks.

They won’t be as strong as precast concrete blocks but will be good enough for many applications and will still have minimal greenhouse gas emissions, especially compared to traditional concrete.

In addition to its sustainability and flexibility, mycelium is one of the cheapest and most readily available eco-friendly building materials.

With proper processing (through maturation, drying, and compaction), it becomes an ideal building material for many projects.

5.  Straw Bales

A stack of straw bales held together with binder twine.
Straw bales are made from the waste stalks of agricultural crops, which can be used to build walls of houses that offer tremendous thermal insulation.

Straw bales are the final item on our list of the most sustainable and renewable construction materials.

Since straw bale construction uses agricultural by-products that most people burn or throw away (the dried stalks of cereal crops left over after harvest), this process makes use of recycled materials that would otherwise go to waste.

They have many benefits for building in an eco-friendly and sustainable way.

The bales are a dense recycled material used to build walls, floors, and roofs. They’re ideal for energy-efficient homes due to their excellent insulating properties, which help to reduce greenhouse gas emissions and energy consumption from heating and air conditioning systems.

Compression is a crucial requirement before using straw bales in construction. The bales need thorough compression to create a solid and stable building material.

The compression also makes the bales denser and more fire-resistant.

Straw bales can come in handy if you want to build on a budget. Besides being cheap, these materials are lightweight and need less energy to transport, cutting down on carbon emissions from delivery trucks.

They also have great sound insulation properties, keeping out nuisance traffic noise or noisy neighbors.

Final Thoughts On the Most Sustainable Building Materials

Using any recycled or renewable material will make your project more environmentally friendly, but if a truly sustainable method of building is your goal, then you should seriously consider using some of the building materials on this list in your new construction project.

However, bamboo is our top pick since it’s a time-tested and proven material with minimal environmental impact.

It’s durable, renewable, and highly regenerative with a low carbon footprint.

Finally, it’s worth noting that durability is crucial when considering a sustainable building material. You want the house to last longer and save you from frequent, costly repairs.

And why not throw in a few solar panels and some good sheep’s wool insulation to make your home even more energy efficient, lowering your heating and air conditioning costs and carbon emissions?

If you found this article interesting, you might also like our article on “29 Sustainable Building Materials You Can Use Today.”

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