The seismic assessment of existing steel structures necessitates the development of practice- oriented engineering models for use in nonlinear static and dynamic analysis procedures. These models should encompass the full range of the anticipated nonlinear behaviour of structural steel elements. Within such a context, this paper provides an overview of the newly developed Chapter 9 of Eurocode 8 Part 3. This chapter includes a comprehensive list of component models that idealize the nonlinear behaviour of the primary and secondary structural steel elements, including columns, steel and composite steel beams, beam-to- column joints, and steel bracings among others. The resistance and deformation models for seismic assessment rely on experimental data, which were systematically collected and curated in structural performance databases over the past two decades within the research group of the author. The paper summarizes some of these models for the nonlinear modeling of both code compliant and noncompliant structural steel elements. A publicly available web-based module has been developed that facilitates the use of the proposed models.