The urban built environment is being transformed by building skins derived from textile architecture. Working from a basis of tensioned membranes, these highly efficient structural forms are now being integrated with multi-disciplinary technologies to form new multi-functional systems that address the needs and global challenges of the urban built environment. The rapid emergence of lightweight building skins is in response to factors associated with climate change, energy, and workplace health and well-being, and is directly linked to advances in material development, analysis tools, and skills in design. These advances, led by European organisations, universities, companies, and SMEs, have, however, been somewhat fragmented. There is now a need to synthesise the current innovations and technologies from which to establish a platform on which the development of new advancements, products, and applications can be stimulated and produced. The aim of the COST Action is to build a coalition of researchers, academics, architects, engineers, contractors, asset owners, and policy makers that creates this platform. It will be achieved through the sharing of expertise, techniques, facilities and data, by establishing technical consensus, and developing European standardisation for the analysis, design, and realisation of multi-functional building skins.