By combining the advantages of conventional reinforced concrete construction with unbonded post-tensioning, a hybrid is created that provides the opportunity to significantly and cost-effectively improve the seismic performance of structural wall systems. The implementation of this hybrid wall system is illustrated using a recently completed seismic retrofit of an existing six-story non-ductile concrete building in Berkeley, CA. Various restrictions during the retrofit led to the use of shotcrete to construct the walls, micropile foundations, and carbon fiber collector elements.