This Study developed library of parts, applied with 3-dimension character which has width, length and height and a reference plane, for the system development of BIM design on housing unit modular. The current BIM software has not the concept of a reference plane or work tolerance in modular, so the development of parts library applied to unit modular has not moved forward. So, we developed, in this study, parts library applied to windows, built-in-furniture, kitchen systems and knock down bathrooms, with a reference plane and work tolerance based on single roon prototype on urban-life-housings. BIM library can utilize changed size and work tolerance of parts, and fabricating reference plane will be created automatically when an engineer puts work tolerance in the BIM library with supplement of some category related to work reference. Through this BIM library development, we consider the part module can be used for housing complex planning, and architectural designers will be able to utilize the BIM library for housing complex design.