IF you inspect the remodeling works including extension which have done in Korea, you will not be able to find out remarkable difference between remodeling works and reconstruction. Because workers remove all the building materials but the frame in remodeling works, construction cost and duration for remodeling and those for reconstruction are almost the same. The government has already announced the guideline for partial remodeling on November 28, 2011. In addition the partial remodeling is expected to be revitalized as regulation revision about vertical extension work after April 25, 2014. In this report, authors talked about the application of modular system on partial remodeling. The abroad cases of modular remodeling and the outstanding issues to resolve are presented.