Polish studio FAAB has developed a concept for a music school in Kraków featuring angular volumes covered with a mossy roof designed to absorb large amounts of airborne pollutants. In response to issues resulting from the city's current poor air quality, the architects proposed covering several of the angled roofs with a natural smog-reducing product developed by German firm Green City Solutions. The technology employs a special moss culture that attracts pollutants such as nitrous oxide, ozone and other particulates, and converts them into its own biomass. Or, as the firm's CEO Dénes Honus suggests, "the moss literally eats air pollution By applying the plants to around 1,300 square metres of the school's external surface area, the architects claim the reduction in air pollution would be equivalent to planting approximately 33,000 trees".