The objective of this research is to demonstrate that parts of decommissioned wind turbine blades can be repurposed for infrastructure applications for a sustainable future of the wind power industry. The purpose of this paper was to develop a methodology to conduct detailed structural engineering design of composite material parts extracted from wind turbine blades. A large section extracted from a 100-m long blade was repurposed as a roof for a small (approximately 40 m²) single-story masonry house. Geometric and material properties were taken from the blade design documents. A three-dimensional graphical model was created from the exterior surface and material layups. The roof was designed using the load and resistance factor design method familiar to civil engineers. Analysis of stresses and defections was conducted using hand calculations and the finite element method. The results of the analyses showed that the roof is within code mandated stress and deflection limits. The methodology developed could be applied to other wind blade repurposing concepts.