This paper introduces the use of elastic displacement floor response spectra to model the seismic performance of non-structural components. This modelling methodology is particularly suited to countries of low to moderate seismicity where infrastructures are generally unprepared for potential earthquake hazards. Components and contents in buildings are typically not designed for seismic protection and are liable to experience rocking or sliding motion in the event of an earthquake. The displacement floor response spectrum has the additional attribute of tracking period-shifts associated with such rocking behaviour. Analyses of the displacement floor response spectra in high-rise buildings demonstrate the significance of contributions by higher modes of vibration that could not always be captured by established code procedures. This also precludes the use of simple static models to predict seismic demand. Results are presented herein to show the sensitivity of the displacement floor response spectrum to a multitude of modelling uncertainties