Colonisation by phototrophic microorganisms causes a range of problems for building façades, while a combination of biological, physical and chemical processes accelerates the decay of materials, giving rise to coloured patinas and encrustations. The scientific literature contains various remediation and prevention strategies employed to limit the extent of biodeterioration. The remediation techniques include the use of biocide solutions and cleaning with UV and laser irradiation, and the use of hydrophobic treatments that decrease bioreceptivity. However, paints and coatings manufacturers mostly deploy various hazardous chemicals (organic biocides, photoactive agents, metallic salts and nanoparticles) [3]. The ...