The building sector is a major water consumer across its lifecycle and plays a critical role in accelerating global urbanisation and the growing water crisis. While architectural approaches have traditionally aimed to exclude moisture, emerging strategies reframe water as an active design parameter. This research explores bioinspired and biologically integrated materials that interact dynamically with moisture. Focusing on Engineered Living Materials, it examines fungal biofilms and microbial inks as responsive, regenerative surface systems. This reshapes the perception of microorganisms in the built environment andadvances probiotic, circular, and climate-resilient architecture.