Bio-Based & Grown
Bio-based and grown materials are those derived from living matter: plants harvested and processed into building products. The harvested group features established materials, ones we’re very familiar with – timber, hemp, cork, straw, wool, cellulose.
These come from forestry or agriculture and have been part of the way we build for centuries. The grown group is newer and smaller: mycelium bound into panels, algae and bacterial materials still growing in their commercial uses. Across the whole family, regardless of the specific material, is a biogenic origin and the properties that come with it, such as the carbon that gets stored during growth.
Bio-Based Materials
The strength of bio-based materials is how they store carbon. They come with a built-in biogenic store that mineral and fossil-derived products simply don’t have. For timber, hemp and straw the amount of carbon kept in the material is noteworthy and a benefit, but it can often be overstated. Whether the stored carbon offsets a building’s footprint depends on how long the material stays in place and what becomes of it afterwards; a hempcrete wall burned at demolition gives its carbon back.
But as with all materials, they don’t come without compromise, and moisture is the downside. These materials are hygroscopic, taking up and giving off water vapour with the conditions around them, which makes them good regulators of indoor humidity but vulnerable to being overexposed to water. Durability comes back to correct detailing: kept dry, cork and timber outlast most finishes, but if not, they will rot. Combustibility is the second compromise, and each material needs to address it differently, such as from the predictable char of mass timber to the renders and treatments that protect straw and hemp.
The grown materials carry one more – mycelium, algae and their relatives are still early, with limited Australian supply, a lack of standards and prices yet to meet scale.
Harvested materials
Hemp
Hemp hurd bound with lime, cast or blocked as insulating, breathable wall infill. It regulates humidity and holds carbon in the wall, though it carries no structural load and takes time to cure and dry.
Cork
Harvested from the bark of living oaks that regrow it over a decade, used as flooring, insulation and acoustic lining. It's resilient, warm and renewable; the compromises are cost and its place as a finish and insulator, not a structural material.
Straw bale
Compressed agricultural straw used as thick insulating wall infill, usually rendered over. It's cheap, high-performing insulation from a waste stream; wall thickness eats floor area and the moisture detailing has to be right or the bales rot.Full hub coming soon.
Bamboo
A fast-growing grass used structurally, as flooring and in engineered panels. It regrows in years rather than decades and is strong for its weight; durability and consistency depend on treatment, and most product is imported.
Wool
Sheep's wool as insulation batts, managing moisture and indoor air where mineral and glass wool can't. It's breathable and handles humidity well; it costs more and needs treatment against pests.
CLT and Glulam
Engineered structural timber, mainly CLT and glulam, that stands in for concrete and steel in floors, frames and load-bearing walls. It builds fast and stores carbon in the structure itself; the compromises are moisture control on site and the fire engineering exposed timber demands.
Grown and cultivated materials
Mycelium
Fungal root structure grown onto agricultural waste and set into insulating boards and panels. It's low-energy to produce and compostable at end of life; it's early, with thin fire and structural data and almost no Australian supply at scale.
Algae based
Materials grown from algae, from bio-resins to panels and pigments, still mostly in research and pilot production. The promise is carbon capture during growth and a circular feedstock; almost nothing is specifiable in Australian building today. Full hub coming soon.
Related reading
CLT House is a retreat designed to weather in the open
Designed by nArchitects, CLT House is a lake house built almost entirely from exposed cross-laminated timber, scaled down from an unbuilt 2008 scheme.
Pipe Dreams: furniture made from surplus CLT and scrap foam
Uniform disks of wood and foam, stacked into a simple geometry, the layers left exposed. Pipe Dreams, by Douglas & Company, takes the way a CLT panel is made and turns it into furniture – a daybed, a bench and an ottoman, all built from surplus materials.
These lights couple offcuts with bacterial cellulose for an ethereal beauty
Designed by Ferma Studio and ReCraft Design Studio – these light pair a reclaimed concrete core sample with a lampshade of bacterial cellulose, grown through kombucha fermentation until it turns soft and semi-translucent.
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We cover beautiful homes and the materials reshaping how they’re built. About Futures is an online magazine for the people who’ll live in what gets made – the ones deciding what to build with, what to keep, and what each choice is really worth.
