MICADO is a modular construction system for dwellings, proposed and developed by a Portuguese construction startup. In brief, it consists of building the dwelling envelope using prefabricated panels. The panels come pre-finished and include adequate thermal insulation. They have a width range between 300 mm to 1200 mm. Each panel is vertically perforated to assist with its on-site assemblage, and accommodate the structural components. The solution allows a wide range of architectural solutions, as well as multiple size openings (e.g., doors and windows). The present paper aims to propose a structural solution for the MICADO construction system. Considering the modular building requirement and using prefabricated panels, assembling a particular type of column-to-beam connections and structural behavior under gravity and seismic loads should be investigated. The structural solution is formed by steel pipe, box, and L-shaped prefabricated profile columns, steel H-shaped pro-file beams, and a steel-deck composite floor. The panels are assembled in the steel profile columns. For this purpose, a twofloor MICADO dwelling is analyzed and designed using numerical modeling, and the structural performance is evaluated. The results show valuable insights into the design and construction of the MICADO method as a steel-based modular structure. 5066COMPDYN 2023 9 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis (eds.