The AEC industry faces persistent challenges such as an aging workforce and low productivity. Off-Site Construction (OSC) and Design for Manufacture and Assembly (DfMA) are emerging as solutions to these issues, receiving significant attention and application in the United States, Singapore, Hong Kong, and recently in Korea. DfMA, a design method that incorporates front loading at the design stage, involves analyzing and disassembling all aspects of a building to design modules optimized for transport and installation. Recognized for its potential to enhance safety, reduce construction time, and increase productivity, DfMA addresses the limitations of OSC construction, particularly errors in the complex design and fabrication stages. To enhance OSC's effectiveness and productivity, this study proposes the development of a BIM-based generative design algorithm. This algorithm aims to rapidly generate numerous combinations of building components using domestic OSC materials, applying DfMA principles at the design stage. The research methodology includes a review of DfMA concepts, analysis of case studies and prior research, investigation and classification of domestic OSC building components, and development of a generative design algorithm for building component combinations. By applying this algorithm, the study seeks to identify and verify the optimal combination of components, considering budget and selected types. Despite DfMA's advantages, issues such as design complexity, uniformity, and assembly errors have been extensively studied. The algorithm introduced in this research could contribute significantly to DfMA-based architectural design, improving fabrication and assembly efficiency early in the design process.