This research aims to develop ultralight nanostructured materials with optimized properties in multiple physical domains. The proposed approach is based on 3-dimensional nanolattices constructed systematically from hollow-core elements. Using subwavelength lattice parameters and hollow construction, the nanolattice can be designed to simultaneously have low density, low thermal conductivity, and high optical clarity. The structure will be fabricated using novel 3D nanolithography techniques and atomic layer deposition, allowing control of structure parameters with nanometer-level precision. Analogous to the modern architectural approach of designing ordered “steel-lattice structures” for optimal mechanical stability in civil infrastructures (towers, bridges, and skyscrapers), this research program will develop the design and fabrication tools to enable “nano-lattice materials.” This research will enable materials with properties that can be directly tailored, and can find applications in ultralight, impact-absorbing, transparent, thermal insulating windows.