Sustainable building materials, such as cross-laminated timber (CLT), rammed earth, hemp masonry, and recycled materials, focus on reducing embodied carbon, improving thermal efficiency, and enhancing durability in harsh climates. Good options include engineered wood, high-performance insulation, and locally sourced natural products, which help reduce energy consumption and environmental impact.
Engineered Timber (CLT & LVL): Cross-laminated timber (CLT) and laminated veneer lumber (LVL) are increasingly popular for structural applications, offering a sustainable alternative to steel and concrete by sequestering carbon.
Rammed Earth & Mud Brick: These materials offer high thermal mass, ideal for temperature regulation, and are sourced from local earth, reducing transportation emissions.
Hemp Masonry: A mixture of hemp hurds, lime, and water, hemp masonry is a highly insulating, breathable, and fire-resistant material that acts as a carbon sink.
Straw Bales: Used for walls, straw bales provide excellent insulation and are a renewable byproduct of agriculture.
Recycled and Reclaimed Materials: Reclaimed timber, recycled steel, and recycled glass reduce waste, while recycled concrete and plastics are being used for durable, eco-friendly structures.
Green Insulation: Options like sheep’s wool, cellulose (recycled paper), and polyester (recycled bottles) improve energy performance and indoor air quality.
Bamboo: Known for its rapid growth, bamboo is used for flooring, cabinetry, and structural elements due to its high strength-to-weight ratio.
Cork: A renewable, durable material ideal for flooring and insulation, offering natural resistance to fire and mould.
Low-Carbon or ’Green’ Concrete: Concrete incorporating waste materials like fly ash or slag reduces the carbon footprint of traditional construction.
Thermal Performance: Materials with high thermal mass (eg concrete, brick, earth) help manage temperature variations, reducing energy usage.
Local Sourcing: Using local materials reduces transportation emissions and supports local economies.
Regulatory Standards: Choosing materials that comply with Australian sustainability standards, such as low-VOC, help to provide better indoor air quality.
Fire Resistance: Materials like stone, earth, and specialised treated timber are valued for their fire-resistant properties. These materials contribute to more energy-efficient and environmentally responsible building practices, reducing long-term maintenance and energy costs.
The least sustainable building materials include conventional concrete, steel, aluminium, and virgin plastics. These materials, having high embodied energy and carbon emissions, contribute significantly to resource depletion and construction waste. Other low-sustainability choices involve non-renewable, high-transport, or non-recyclable products, such as PVC, uncertified timber, and certain synthetic insulation materials.
Concrete (Conventional): Despite its high thermal mass, standard concrete has a massive carbon footprint due to cement production, which is a significant source of CO2 emissions.
Steel and Aluminium: These require immense energy for mining and manufacturing, making them high in embodied energy, though recycling can reduce this impact.
Virgin Plastics/PVC: Used in piping, flooring, and insulation, these are petroleum-based, non-renewable, and often difficult to recycle, contributing to pollution.
Uncertified/Imported Timber: Logging native forests or transporting timber across oceans has high environmental costs, making it less sustainable than local plantation or reclaimed timber.
Conventional Brickwork/Masonry: While durable, they are energy-intensive to manufacture and transport.
High-VOC Paints and Adhesives: These contribute to poor indoor air quality and are often sourced from unsustainable petrochemicals.
To improve sustainability, industry trends in Australia emphasise reducing waste (which accounts for 44% of total waste) and choosing materials with lower embodied carbon, such as engineered wood (CLT), recycled metal, or, when necessary, using high-impact materials for their thermal mass benefits.