PART 1. DESIGN CRITERIA AND CODIFICATION 1 Seismic design principles 1.1. Capacity design criteria 1.2. Dissipative structures and typologies of steel structural systems 1.3. State of European seismic codification and new perspectives 1.4. Conceptual design 2 Introduction to EN1998-1: Explanation and commentary 2.1. Seismic action 2.2. General recommendations for seismic resistant structures 2.3. Analysis methods 2.4. Detailed provisions to design steel structures PART 2. WORKED EXAMPLES 3 Multi-storey building with moment resisting frame 3.1. General data 3.2. Design and safety check under gravity loads 3.3. Design and safety check under seismic actions 4 Multi-storey building with concentric brace frame 4.1. General data 4.2. Design and safety check under gravity loads 4.3. Design and safety check under seismic actions 5 Multi-storey building with eccentric brace frame 5.1. General data 5.2. Design and safety check under gravity loads 5.3. Design and safety check under seismic actions 6 One-storey industrial building 6.1. General data 6.2. Design and safety check under gravity loads 6.3. Design and safety check under seismic actions PART 3. STUDY CASES 7 The Bucharest Tower Center 7.1. General data 7.2. Conceptual Design 7.3. Design and safety check under seismic actions 7.4. Credits 8 The fire station of Naples 8.1. General data 8.2. Conceptual Design 8.3. Design and safety check under seismic actions 8.4. Credits REFERENCES