Integrating greenery systems and active insulation into adaptive building envelopes for enhanced sustainability and thermal resilience

Urbanization has intensified climate change and exacerbated urban heat island effects, increasing energy burdens and heat stress. This underscores the urgent need for thermally resilient and adaptive building solutions. As key contributors to heat gain, building roofs present critical opportunities for enhancing thermal performance. While effective, static insulation in passive techniques hinders adaptive thermal regulation under fluctuating environmental conditions. In response, this study proposes a novel self-adaptive roof that integrates active insulation systems (AISs) and greenery systems as a responsive building envelope (RBE) configuration to leverage ambient thermal energy. Simulation studies were conducted on a representative residential building with various roof configurations across very hot to mixed climate zones to evaluate its performance in energy savings, thermal comfort, and thermal resilience. The RBE-based roof achieved up to 87.9 % monthly energy savings and 10 % improvement in annual long-term thermal comfort, outperforming traditional green roofs. Unlike passive techniques with nonlinear or diminishing gains under increasing insulation, its performance improved consistently with higher insulation levels. AIS with intermediate insulation suggested a potential to balance performance and cost. Moreover, it maintained a safe heat index and superior passive habitability throughout heatwave-induced power outages, surpassing the baseline and green roof cases. A concise life-cycle cost-benefit analysis and water-energy-carbon trade-off assessment further confirmed its promising economic viability and context-sensitive environmental performance. This uniquely integrated system maximizes climate-adaptive synergistic performance while addressing limitations of passive cooling, demonstrating strong potential as a scalable and resource-efficient resilient cooling strategy, particularly in regions with minimal reliance on freshwater irrigation.