This graduation project takes place in a vacant heritage building that was a former V&D department store building in the center of Leiden. The studio begins with collective research on the Spatial Building Typology research of the former V&D department stores buildings. The main individual research and design strategy are based on Petzet and Heilmeiyer's (2011)’s strategy of Reduce Reuse Recycle (3R) in approaching heritage building. For the program, the study is based on the Reduce Reuse Recycle Redesign Reimage by (Esty&Winston, 2006). Therefore, keeping the retail identity of the building was chosen to reuse the circulation system and column-defined space character of the building. However, to reuse the building as a whole, a sustainable program that adjusts to today’s needs was adapted to the building which is retail as an offline showroom that directly connects to the office. A library was added as the public part of the building. A reimagined retail building. The redesign of this mixed-use building itself is based on the strategies with green intervention as the spatial language that embodies the principle of Reduce Reuse Recycle strategy.