Since water-use characteristics and the new technology of plumbing fixtures have changed, it is significant to educate a facility manager in the characteristics of these systems. Also, it is necessary to provide a better understanding of parameters that may determine the suitability of retrofitting plumbing fixtures. The 1992 Energy Policy Acts enforces 1.6-gallon per flush (gpf) for a toilet and 1.0 gpf for a urinal. In response to the regulation, the purpose of this research is to measure automatic flush valve performance (gpf) of fixtures in a mixed use classroom building at Texas A&M University. Water consumption (gpf) among three types of fixtures; low-consumption manual, old optic automatic and improved optic automatic systems are measured by using a magnetic water flow meter. The data in the study were analyzed to determine compliance with plumbing standards and to compare the average water volume per flush cycle of toilets in the men??s and women??s restrooms. Finally, the results of the data show that retrofitting the old optic automatic with the improved optic automatic system resulted in water savings of about 15.80% in toilets, and urinals.