A computational study of a metamaterial (MTM)-on-glass composite is presented for the purpose of increasing the energy efficiency of buildings in seasonal or cold climates. A full-spectrum analysis yields the ability to predict optical and thermal transmission properties from ultraviolet through far-infrared frequencies. An opportunity to increase efficiency beyond that of commercial low-emissivity glass is identified through a MTM implementation of Ag and dielectric thin-film structures. Three-dimensional finite difference time-domain (FDTD) simulations predict selective nonlinear absorption of near-infrared energy, providing the means to capture a substantial portion of solar energy during cold periods, while retaining high visible transmission and high reflectivity in far-infrared frequencies. The effect of various configuration parameters is quantified, with prediction of the net sustainability advantage. MTM window glass technology can be realized as a modification to commercial low-emissivity windows through the application of nanomanufactured films, creating the opportunity for both new and after-market sustainable construction.