Water sustainability potential in a university building – Case study

•Rainwater harvesting is important to water sustainability.•Recycling and efficient reuse of water is economically feasible.•Different water resources should be considered to reach sustainability.•Water savings strategies are significant to efficient management. Water is a vital element for the survival of humanity. However, due to the unequal distribution and irrational use of water resources, several regions face problems related to water scarcity. Given this scenario, different sources of water reuse have been studied. Condensed water from air conditioning and gray water, although still little explored, have great potential for complementing the water resources used. Thus, this research analyzed the reuse potential of gray water, rainwater reuse and water from air conditioning systems, as well as proposed measures to minimize the consumption of drinking water in the main building of the Department of Agricultural Engineering at the Federal University of Viçosa, Minas Gerais, Brazil. Considering that the estimate of the current monthly water consumption of the building is 172.42 m3, it was estimated that about 68.6% could be saved by water reuse. By adopting water reuse and the proposed measures, such as tap aerator and coupled discharges, the department will also contribute to the preservation of water resources, which are already scarce in the city of Viçosa and reduce expenses. Furthermore, the building may become a reference in water reuse for other buildings and for proposing water reuse legislation.