In recent decades, the construction industry has faced significant challenges, including declining productivity, material waste, and increasing environmental impacts. These issues highlight the necessity of transitioning toward industrialized and sustainable construction systems. Although prefabricated and modular construction methods have advanced considerably, many existing systems still lack an effective balance between structural performance and architectural spatial flexibility. This research addresses this gap by proposing an innovative steel modular structural system that integrates structural requirements with architectural spatial quality. The system is designed using light-gauge steel profiles and prefabricated panels, where each module functions as an independent unit produced in a factory-controlled environment and assembled on site through mechanical dry connections. The research adopts a design-based research methodology centered on the development of a parametric model within the CATIA. This process enabled the integration of architectural, structural, and mechanical, electrical, and plumbing (MEP) components within a unified digital prototype. The structural behavior of the proposed model was evaluated through Finite Element Analysis (FEA) using ABAQUS, monitoring key indicators such as stress distribution, displacement, and lateral stiffness across various modes. The force-displacement and stress-strain results revealed a maximum lateral displacement of 0.226 mm and an equivalent lateral stiffness of 10.93 KN/mm. Furthermore, the peak stress at critical connection points was recorded at 15.57 MPa, which remains well below the steel yield strength (235 MPa). Findings confirm the system's adequate lateral stiffness and structural integrity, supporting its potential for incremental spatial expansion and as a viable model for the industrialization of future housing.