The Environmental Case for Wood

Renewable by nature

Trees can be replanted and regrown. With good forest management, timber can be harvested indefinitely without shrinking the resource. Other structural materials depend on finite resources:

• Steel: iron ore mined from finite deposits.
• Concrete: quarried limestone and sand, with large CO₂ emissions from cement production.
• Aluminium: bauxite, refined in one of the most energy-intensive industrial processes.
• Brick: mined clay fired in high-temperature kilns.
• Plastic composites: made from petroleum.

Once extracted, those resources are gone or need energy-intensive recycling. Forests regrow.

Carbon storage

As trees grow they absorb CO₂ through photosynthesis and turn it into wood. That carbon stays locked in the timber for the life of the building, which can be decades or centuries. Dense hardwoods store more carbon per piece and last longer in service.

Using timber in place of high-emission materials has a double benefit: the carbon stored in the wood, and the emissions avoided by not producing the alternative. But it depends on sourcing. If forests are harvested faster than they regrow, they can release more carbon than they capture. See how sustainable forest management is verified.

Processing energy compared

Embodied energy is the total energy needed to produce a material, from extraction to processing and transport. Wood has among the lowest embodied energy of any structural material.

• Timber: harvest, transport to the mill, sawing and kiln drying. Drying is the most energy-intensive step, and it is still modest. Many mills burn their own sawdust, bark and offcuts to power kilns.
• Steel: mining iron ore and coal, then heating to around 1,500°C in blast furnaces, refining, casting and rolling.
• Cement: quarrying, crushing and heating limestone and clay to around 1,450°C, a chemical reaction that itself releases CO₂.
• Aluminium: refining bauxite to alumina, then high-temperature electrolysis.
• Brick: firing clay in kilns at around 1,000°C for hours.

Because wood processing needs relatively little energy, it is also much easier to run on renewable power than steel or aluminium smelting.

Forests, biodiversity and water

The key difference is between sustainable forestry and deforestation. Deforestation clears forest for other uses such as farming or housing. Sustainable forestry keeps the forest: harvest rates never exceed growth, harvested areas regenerate, and reserves, wildlife corridors and habitat trees are protected. Well-managed Australian forests regrow, and areas harvested years ago are healthy forest again.

Australian forestry standards also protect water: buffer zones around waterways, roads designed to prevent erosion, properly built stream crossings, no machinery in streams, and fuel and oil controls. Timber needs no water in processing, while concrete, steel and aluminium production all use large amounts and can pollute waterways. Mining for those materials permanently changes landscapes; forests grow back.

Durability and end of life

Correctly selected, installed and maintained, hardwood can match or outlast other materials. Class 1 species such as Red Ironbark and Tallowwood have an expected life of 25+ years in ground and 40+ years above ground, and much longer when fully protected. Concrete, steel and aluminium all degrade too, through rebar corrosion, rust or galvanic corrosion, and need protection and maintenance. See durability classes explained.

Large timber members also behave predictably in fire: the outside chars and protects the core, so engineers can design for it.

End of life

• Reuse: beams, flooring and framing are often salvaged for new buildings. We supply recycled hardwood.
• Recycling: chipped for particleboard, MDF, mulch or biofuel.
• Biodegradable: wood decomposes and returns nutrients to the soil.
• Energy recovery: burning wood releases only carbon recently captured from the air.

Concrete is usually crushed for road base or sent to landfill, and plastic composites often can't be recycled.

People and communities

Wood indoors helps regulate humidity, and natural timber doesn't release the chemicals that some manufactured finishes do. Australian forestry and sawmilling also support long-term jobs in regional communities.

Questions to ask your timber supplier

• Where does this timber come from?
• Is the forest certified, and under which scheme?
• What provenance documents come with it?
• Is it legally sourced under the Illegal Logging Prohibition Act?
• What is the species' durability class for my application?
• Are there recycled or reclaimed options?

We're happy to answer these for any timber we quote. Talk to us about sustainable timber, or browse our other timber guides.