Wood stores, rather than emit, carbon dioxide. Combining its many economic and environmental benefits, wood provides a unique framework of sustainable materials. Wood is composed of numerous aligned cellulose fibers with hierarchical structure ranging from macroscale to ångström scale, offering immense opportunities across diverse length scales. My long-term goal is to apply fundamental science and engineering to establish a toolbox of natural materials for sustainable solutions for energy, water, environment and devices. In the proposed work, we seek to unravel the multiscale process-structure-property relationships of wood and cellulose, and gain unprecedented control over the materials properties in the thrusts of sustainable built and energy-water nexus. In addition to establishing the necessary knowledge base, we also aim to build the channels between lab technologies and societal impact towards attaining the long-term goal.