Globally, the construction industry is one of the most polluting sectors. This is why sustainable building materials are not just trending, but key in reducing carbon dioxide emissions and slowing climate change. This article’s spectrum of sustainable building materials, from alternatives to traditional concrete and recycled products to innovative eco-friendly timbers and integrated photovoltaic materials, will help transform your projects into models of environmental stewardship.

1. Recycled steel, plastic, glass and rubber

Recycling is one of the most eco-friendly methods of creating sustainable building materials. Steel is the world’s most recycled construction materials with around 40% of all steel being made using pre-used steel. The advantages include minimal waste and no loss in strength or durability after recycling. Plastic is recycled and enhanced with other materials to produce numerous construction essentials such as fencing, bricks, lumber, concrete, gravel, floor and roof tiles, concrete, and even gravel. Recycled glass uses less energy in production than new glass and recycled rubber can often be used for landscaping, asphalt and flooring.

2. Bamboo

Bamboo has been used extensively as a sustainable building material for centuries, predominately in the Far East, however, it is gaining popularity in Western construction projects. Bamboo has many attractive properties. Extremely strong and flexible, bamboo is the fastest growing plant on the planet and regrows incredibly fast in just 3 to 5 years resulting in good availability. Fully biodegradable, bamboo is eco-friendly and antibacterial provided it is not processed using chemicals. While it has many sustainable benefits, a word of caution is also advised. As raw bamboo is soft and not naturally weather resistant. Hence to make it durable enough for outdoor applications such as decking, it often undergoes intensive processing, including: heat treatment, glue and resin bonding and chemical treatments for moisture, UV and insect resistance.

3. Ferrock

Ferrock is a wonderful sustainable building material that is a perfect alternative to concrete. Manufactured using a mix of recycled steel, dust silica from ground up glass, lime powder and water, it is five times stronger than traditional concrete. It is incredibly sustainable as it is carbon-negative. During the manufacturing of Ferrock, the process has zero impact on the environment, in fact, as opposed to emitting CO2, Ferrock actually absorbs it. This sustainable alternative to concrete made from recycled waste material reduces landfill and is ideal for building anything from buildings to bridges and roads.

4. Sheep’s wool

When constructing sustainable buildings and homes, insulation has become an increasingly important consideration, particularly in times of high energy prices. Sheep’s wool is the only naturally occurring sustainable insulating material capable of retaining heat and giving protecting from the cold and moisture. Sheep’s wool is one of the industry’s most sustainable building materials which has the natural ability to regulate humidity, stabilize temperatures and purify the air. It is fire resistant and absorbs noise, too.

5. Accoya wood

Softwoods are sustainable building materials because of their fast growth-rate; however, they have a relatively short lifespan and are susceptible to swelling, warping, twisting and decay. Accoya wood is made from softwood, but that is where the similarity ends. Water is timber’s greatest enemy, but Accoya’s special acetylation process modifies the molecular structure of softwood’s cell walls to prevent them from absorbing water. This makes Accoya modified wood incredibly durable, dimensionally stable, and rot-resistant. The acetylation process extends the wood’s life which is why Accoya wood comes with a warranty of up to 50 years. Accoya only uses trees from FSC certified forests and no toxic chemicals are used in the acetylation which makes it a contender for one of the top 5 sustainable building materials.

6. Clay brick

Traditional clay bricks are one of the construction industry’s most prevalent sustainable building materials and have been used for centuries. What makes them so attractive is the fact that they are strong, durable, low maintenance and can be easily recycled to make new bricks. What makes clay one of the most sustainable building materials is the fact that clay is naturally abundant so clay bricks can be manufactured locally, cutting transportation costs and fuel emissions. New advanced manufacturing processes and advanced kiln technology also help to reduce the energy consumption and greenhouse gas emissions that occur when firing clay bricks.

7. Cork

Cork isn’t a material that immediately springs to mind when talking construction, but it is one of the most versatile of sustainable building materials and is highly resistant to water and absorbs vibrations. Cork can be used to create anything from wall coverings, countertops and insulation to roofs, shingles and acoustic tiles. What makes it so sustainable is that cork is the bark of a cork oak tree and therefore it is harvested without felling the tree. Light, malleable and easy to work with, cork is a builder’s dream. Also, because its cell structure stores carbon it is one of the most eco-friendly and sustainable building materials you can opt for.

8. Plant-based Biofoams

Insulation is high on the list of priorities when building any building these days as it directly affects the energy efficiency and livability of properties. Spray foam insulation is quick and convenient to install which makes it highly attractive to developers, however, traditional spray foams rely heavily on petrochemical products and are a potential health risk for anyone installing them. Plant-based biofoams are equally efficient sustainable building materials which are made from plants including bamboo and hemp, and can reduce the reliance on petroleum derived materials by up to 25%. Add to that the fact that, each year, a typical home insulated by spray foam can make considerable energy savings and cut its carbon emissions. Rigid plant-based biofoam panels are also widely available.

9. Hemp

The humble hemp plant has a big part to play when it comes to sustainable building materials. Natural, sustainable and breathable, it can be used to create anything from sustainable concrete and building panels to highly efficient and eco-friendly insulation. Hemp fiber panels are formaldehyde-free, safe and hygienic to handle, mould and water-resistant. HempCrete is a mixture of hemp fibers, sand and lime and is available in light and easy to handle blocks that are great insulators and resistant to fire and pests. HempWool is a fantastic sustainable insulation material too which saves energy, reduces sound and lowers the carbon footprint of a property.

10. Cross-laminated timber (CLT)

Cross-laminated timber is gaining a lot of traction in the building industry and presents a more eco-friendly alternative to steel and cement. CLT consists of several layers of solid wood which are glued crossways on top of each other. This gives it incredible structural strength and stability, making it ideal for use in constructing ceilings, roofs and walls. CLT actually binds carbon dioxide making it one of the most eco-friendly and sustainable building materials and its waste can be easily recycled. Cross-laminated timber helps reduce energy costs, is fire-resistant, is quick and easy to work with, too.

11. Cob

Sometimes you need to look back to the past for sustainable building materials. Cob building has been around for thousands of years and cob houses were highly popular in the UK 500 years ago. Cob was made by pulverizing soil, straw, sand and lime the “cobbed” by treading on it to create a building material that was strong durable and containing almost zero carbon. Today, modern versions of cob are available which have a mixture that is more efficient at absorbing and trapping heat. Totally recyclable and biodegradable, cob walls offer excellent thermal insulation and help to regulate internal temperatures. It is one of the oldest and most natural sustainable building materials available.

12. Mycelium

Fungi in a property is usually seen as a problem, however, mycelium – which is the root like structure of fungi – is one of the most exciting, innovative and sustainable building materials of the future. Mycelium is grown on agricultural waste, is relatively low-cost, biodegradable, captures and stores carbon, and can be composted when its life ends. It can be used as an alternative to concrete and can be used for non-load bearing applications such as interior wall paneling, insulation, door cores and flooring. Super-strong and incredibly eco-friendly, mycelium can be molded into shapes and is fire, mold and resistant.

13. Reclaimed and recycled wood

Wood is one of the most widely used building materials in the construction industry and it is easy to see why. Plentiful, natural and easy to use, wood ticks a lot of boxes. But could it be more sustainable? Increasing its lifespan by modifying timber, like Accoya modified wood, makes it much more sustainable. Compared to new timber, reclaimed and recycled wood has a lower impact on the environment and also reduces waste and diverts wood from going to landfill. Reclaimed wood has another advantage in that it is more characterful than new wood and possesses unique charm through its rustic patina from its previous life.

14. Enviroboard

Enviroboard is one of the most versatile and durable sustainable building materials that presents a viable alternative to traditional materials like particleboard and gypsum. Made from a combination of magnesium, sawdust, and fiber cloth, Enviroboard is the perfect environmentally-friendly choice for wall lining, roof lining, and underlay systems. Stronger than traditional boards, Enviroboards don’t warp as they are water-resistant – plus, they are resistant to fire and insects, too. Fully recyclable, Enviroboard is non-toxic, safe to install and as they are dried naturally when manufactured, they don’t create any extra carbon emissions.

15. Sustainable concrete

We mentioned HempCrete earlier, but there are several other sustainable building materials that have all the advantages of concrete, but have a lower impact on the environment. Instead of cement, AshCrete uses over 95% recycled materials including fly ash and bottom ash in its manufacture, creating smaller pores and making it almost twice as strong as traditional concrete. TimberCrete replaces the most energy-intensive ingredients of concrete with recycled sawdust. This makes highly durable and fire-resistant blocks that are light to transport and are much better insulators than concrete, brick and clay – TimberCrete is even bulletproof, too.

16. Building-integrated photovoltaic materials (BIPV)

Sustainable building materials can not only reduce the amount of energy a building uses, they can also generate energy. Building-integrated photovoltaic materials generate solar power by seamlessly integrating technology into the facades, tiles, shingles, skylights, windows and siding of buildings. These innovating sustainable building materials and systems are not only capable of generating clean electricity, they also provide valuable protection from the sun, noise and rain. BIPV systems can be incorporated in new constructions or retrofit to existing properties to help create green net-zero energy buildings

17. Straw bales

The use of straw bales as sustainable building materials spans from the Palaeolithic era all the way to present day. Why is its use so enduring? Straw is available worldwide which means most areas have local access to it which cuts down carbon emissions from transportation. Straw bales are excellent low-cost insulators and as a by-product of agriculture, they are a renewable resource. They regulate indoor temperatures and reduce the need for energy intensive heating and cooling. Installed correctly, straw bales are also durable, fire-resistant, contain no harmful toxins and are easy to handle. Best of all, they are 100% biodegradable, making them one of the most sustainable building materials available.

18. Earth blocks

Not dissimilar to cob, earth blocks are sustainable building materials made using completely natural elements. A mixture of locally sourced aggregate, dry subsoil, clay and sand, these bricks – which are also called compressed earth blocks – are dampened and then compressed at high pressure to form blocks. Being pressed, their manufacture produces much lower carbon emissions than energy-intensive firing of bricks or concrete production, in fact, they can even be produced on-site. Naturally strong, earth blocks can withstand the elements, are fire-resistant and also absorb then release moisture to regulate indoor humidity.