Insulation has become a good answer to the current environmental crisis. We are blowing mainly glass wool, that is sold 'loose' with no binder. Heavily compressed for transporting, it is applied by being blown with a blowing machine. It has excellent insulating properties, cheap, quickly installed, non-flammable and with good acoustic properties. Originally intended for loft spaces and attics, the product has quickly become usable for house walls. A product concept to meet North European climatic requirements to keep buildings energy efficient.