This International Standard specifies principles of evaluating seismic actions for the seismic design of buildings, towers, chimneys and similar structures. Some of the principles can be referred to for the seismic design of structures such as bridges, dams, harbour installations, tunnels, fuel storage tanks, chemical plants and conventional power plants. The principles specified in this International Standard do not cover nuclear power plants, since these are dealt with separately in other International Standards. In regions where the seismic hazard is low, methods of design for structural integrity may be used in lieu of methods based on a consideration of seismic actions. This International Standard is not a legally binding and enforceable code. It can be viewed as a source document that is utilized in the development of codes of practice by the competent authority responsible for issuing structural design regulations.