Potentials of hydroactive lightweight façades for urban climate resilience

Extreme heat and heavy rainfall events with severe inundations have a significant impact on urban architecture, resulting in considerable personal injuries and material damage. Nowadays, the proportion of façade surface in urban areas with tall buildings is substantially larger than the proportion of horizontal roof or ground surface areas. A high leverage effect on climate resilience and sustainability of buildings and cities can therefore be attributed to the building envelopes. Whereas the majority of existing façades are designed to provide only minor qualities at a district or urban level, research at the Institute for Lightweight Structures and Conceptual Design (ILEK) at the University of Stuttgart focuses on development of a new type of hydroactive lightweight façades incorporating climate change mitigation and adaptation strategies. A textile- and film-based façade element called HydroSKIN is capable of providing a retention surface on the envelope of the building. With a minimal amount of embedded mass, energy, and CO₂ emissions, the façade add-on element is suitable for both new and existing buildings. HydroSKIN combines rainwater harvesting (RWH) and run-off water reduction by retaining the precipitation water that strikes the façade with a time-delayed evaporative cooling (EC) of the building and its environment.