We note the limitations of the classical Response Spectrum Method (RSM) for design of earthquake resistant structures in the near field of strong earthquakes. The main one is that the RSM is based on the largest peak of the relative response, and does not consider the duration of strong motion. To illustrate an alternative approach the recorded response of a seven-story reinforced concrete hotel (VN7SH) in Van Nuys, California, damaged during January 1994, Northridge earthquake is described in terms of one-dimensional layered shear beam model, undergoing nonlinear wave excitation. We use this model to show the time and space variations of wave energy and of power in the building response, and to set a physical basis for a new design method based on the power of strong motion pulses propagating through a building.