Globally, cities are grappling with intensifying heat stress and rising cooling energy demand, with the impacts disproportionately falling on populations in the Global South, where access to adaptive technologies remains limited. We present ‘Relative Humidity–Temperature Profiling (RHpT)’, a scalable climatic screening framework that identifies windows of opportunity in which humidity-responsive materials can enable passive, sensor-free building adaptation. Using two climatically distinct cities (New Delhi and Newcastle upon Tyne), we show that RHpT can identify seasonal and diurnal conditions suitable for actuation, and that these are validated through laboratory characterisation of larch veneers and dynamic building simulations. In non-optimised retrofit scenarios, RHpT-guided façades reduced cooling demand by up to 10%. More broadly, RHpT offers a transferable method for cities to assess the feasibility of bio-based adaptive envelopes, connecting climate logic to material thresholds and energy outcomes. This approach demonstrates how bio-responsive, low-cost design strategies can contribute to just and low-carbon urban resilience.
Debnath et al. (Sun,) studied this question.