The growing awareness of the benefits of biomaterials has led ISOBIO, a European research project, to focus on developing insulating solutions relying on bio-based aggregates such as straw or clay.
The ISOBIO scientists say that by using locally sourced plant waste, it may be possible to halve the embodied energy involved in producing insulation panels. Plant waste has the added bonus of locking CO2 inside the insulation material, reducing its overall carbon footprint.
A strong point with biomaterial insulation is the comfort factor. Breathability is key in keeping a building’s occupants happy and healthy. Too dry, and people will suffer from dry eyes, skin and throats. Too humid, mould will make an unwelcome addition to the household.
According to project partner Patricia María Pérez Tarancón at Acciona, Madrid, Spain, "The hygroscopic properties of bio-based insulation mean that they can absorb and store moisture from the surrounding air. The material behaves as a moisture buffer. This softens the relative humidity changes in the environment, reducing risks from common pollutants such as bacteria, viruses, chemical reactions, allergies and respiratory infections, as well as reducing the need for air-conditioning." Furthermore, as one expert points out, bio-based materials can also be a healthier option.
The scientists working in the ISOBIO project also hope to develop bio-based binders –such as starch and casein– instead of mineral-based products like lime. "We will be exploring novel bio-based binders to see if they will be fit for purpose," says Michael Lawrence, lecturer in low carbon design in the University of Bath, UK, and ISOBIO principal investigator. "We’ll also be developing ways of making binders go further, or of improving the characteristics of bio-based binders," he says.
However, cost is a major barrier to this technology's widespread adoption. The research consortium hope to overcome this hurdle by reducing the total cost of insulation by an expected 15% and the lifetime energy cost of the building by at least 5%.
For further information, please visit the relevant European Commission website.