Currently, clean water and environmental issues are becoming a major concern because the source of these issues mostly comes from buildings, one of which is offices. Most buildings apply the energy saving concept, and there are still few that apply the water conservation concept, especially in Indonesia. The lack of references for office buildings that implement water conservation makes it difficult for Indonesian architects to implement this concept. Therefore, this study aims to compare buildings that apply water conservation by looking for data related to similar projects that are used as a reference in a project in Indonesia. In this study, a comparative study of projects in Indonesia was carried out with several projects abroad that implemented the water conservation concept. The projects were examined based on six aspects of applying the concept of water conservation, as well as the layout of reservoir, and comparison of the water tanks amount needs. The results of this study show that projects applying water conservation aspects in Indonesian outbuildings are more diverse compared to buildings in Indonesia, which causes the percentage of water conservation in Indonesian outbuildings to be much more optimal, the location of water storage in all projects is mostly in the basement, and the average amount of water storage is 2.5 to 4 times the water needs.