The structural performance of historic buildings is a critical concern with respect to safety and functionality. While the decorative surface fabric of a building is the most visible manifestation of its architectural value, the integrity of these surfaces may be affected by the performance of the underlying structure. When symptoms of inadequate structural performance are manifested by cracked or displaced finishes, a structural engineer is generally consulted in order to evaluate the structural integrity of the building. More recently, engineers have begun to look towards more sophisticated analytical methods in order to help better simulate and understand structural behavior. In particular, Finite Element Analysis (FEA) has become increasingly prolific in the field. This thesis sought to critically analyze the capabilities and limitations of FEA in its application to the diagnostic of historic structures, utilizing the Wagner Free Institute of Science as a case study. Finite element analysis was utilized to investigate the structural performance of the roof structure--inclusive of the arched trusses, the vaulted roof assembly and the plaster.