Wool

Wool is one of the oldest building materials still in use, and one of the most capable: it insulates, buffers humidity by absorbing and releasing moisture, and binds indoor pollutants rather than off-gassing them. The constraints are real too – it needs treatment against pests, and it sits at a price and supply scale that keep it a considered choice rather than a default.

Start with the full guide: Wool as a building material: composites, and how wool performs. Also, see how wool bio-composites are being used in lighting and wool products.