For buildings which are located in seismic areas with complex geometric shapes , specific structural systems and important usages we can not rely on the existing regulations.

In these buildings , the most appropriate and reliable solution is seismic design based on performance.

In this way , we can previse ( forecast ) structure's performance and behavior against the level of earthquake hazard by using plastic structure's analysis mainly. And finally (ultimately ) design the structure in such a way that it maintains it's saftey during and after the earthquake.