Eco-friendly building materials in Australia: algae bricks and oyster shells
Australia is at a pivotal moment in the transformation of its construction sector. For decades, the industry has relied on traditional materials such as cement, steel and concrete, whose production generates millions of tonnes of carbon dioxide emissions every year. In a global context marked by climate urgency, Australian researchers, architects and companies are turning to eco-friendly building materials that not only reduce environmental impact but also open up new aesthetic and functional possibilities.
Among the most striking innovations are bricks made from algae and walls composed of recycled oyster shells, two proposals that aim to demonstrate that it is possible to build more sustainable homes and buildings that are circular and in harmony with nature. However, these advances are still in the experimental phase and face significant challenges in terms of cost, regulation and scalability.
The context: why invest in biomaterials?
The construction sector is responsible for a substantial share of global greenhouse gas emissions. Producing cement and steel requires enormous amounts of energy, and the process releases pollutants that are difficult to offset. In response, interest has grown in biomaterials, materials obtained from living organisms or organic waste.
These materials offer a key advantage: instead of emitting carbon during production, they can store it and even continue absorbing it throughout their lifespan. The concept of so-called “living materials” has gained traction, as they not only fulfil structural functions but also integrate natural processes into architecture.
In addition, biomaterials help valorise agricultural and food industry waste, reducing pressure on landfills and promoting the circular economy.
3D-printed algae bricks
One of the most surprising developments in this field is bricks made from microalgae. Their production process combines biotechnology and 3D printing techniques, resulting in pieces with organic shapes and natural colours that evoke traditional decorative blocks, but with a much lower environmental footprint.
These bricks have the potential to become carbon-negative materials, as the algae used in their production absorb CO₂ during cultivation. However, manufacturing remains challenging: printing each unit is slower and more expensive than conventional industrial processes, limiting competitiveness.
Despite these limitations, the concept of algae bricks opens the door to a new paradigm in which buildings actively contribute to planetary regeneration.
Oyster shell walls and marine finishes
Another innovative front in Australia is the use of oyster shells from the food industry. Every year, tonnes of shell waste end up in landfills, and efforts are now underway to give them a second life as eco-friendly building materials.
By crushing and combining these shells with seaweed and other binders, a material is obtained with strength and appearance similar to concrete, but with a speckled green and grey finish that provides unique aesthetic value. It is being tested in applications such as acoustic panels, interior tiles and wall cladding.
At the same time, some Australian companies have developed decorative interior coatings made from recycled shells. Although more expensive than conventional finishes, their durability and sustainability make them attractive to architects committed to green innovation.
Other eco-innovative materials in Australia
Algae bricks and oyster shell walls are not the only proposals underway. Across Australia, other alternatives are being explored:
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Living materials: walls and surfaces covered with organisms such as moss or algae that continue absorbing carbon after installation.
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Bamboo and mycelium panels: mycelium acts as a natural binder combined with plant fibres, producing resistant and biodegradable panels.
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Straw construction: homes built with straw bales and prefabricated panels, offering renewable materials and good fire performance.
These innovations highlight the sector’s dynamism and the diversity of solutions emerging for the coming years.
Main challenges: cost, certification and regulation
Despite their promise, biomaterials face three major barriers to mass adoption:
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High cost: many materials rely on experimental or manual processes.
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Lack of certifications: existing building codes are designed for traditional materials.
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Regulatory rigidity: companies must navigate complex approval processes.
By contrast, some European countries have progressed faster by supporting bio-based materials through dedicated policies and markets.
Outlook and future
Interest in eco-friendly building materials is not a passing trend but a necessary response to the environmental crisis. In Australia, more professionals recognise that the future of construction lies in reducing dependence on cement and adopting regenerative solutions.
While these projects are still niche, they are likely to become mainstream in the coming decades as costs decrease and regulations evolve.
