A method to extract a building’s capacity curve using acceleration data for post-earthquake safety evaluations had been developed, along with adjustments to account for buildings without sensors on some floors. However, the allowable deformation safety limit is also dependent on the deformation mode and needs to be accurately estimated for buildings without sensors on some floors to estimate the safety level. This study proposes a conceptual methodology for addressing this issue based on various features of elastic and inelastic response, and possible research avenues to address these issues are identified.