Nearly two billion kilograms of wool go unused every year — stockpiled, burned or buried. Jonathan Grinham’s research group at Harvard breaks the fibre’s keratin down with an alkaline treatment, then binds it with citric acid and heat into rigid, resin-free tiles: a light insulating back layer and a dense, weatherproof face that can be fixed to existing walls without opening them up. Shown at the Oslo Architecture Triennale, it’s a retrofit material that is fire-resistant, antibacterial and made from a farm by-product. Source: Dezeen