Recently, Han-ok is being reconsidered as a type of desirable housing. In order to modernize Han-ok, it is necessary to manage building informations with an organized system based on a data handling technology, such as BIM. Three dimensional Object-based parametric modeling technology enables to model irregular and atypical geometries of Han-ok in a very efficient way. With parametric modeling technology, architects can control the dimension of the digital model of their building through parameter which is mathematically variable. In parametric model, the dimensions of each parts of a building are not only defined as parameters, but also the relations among them are defined as functions. Architects can change their design with less effort and cost by the support of automatic calculation. Therefore, the purpose of this study is to devise a parametric modeling methodology which is optimized to the principle of Han-ok.