A water saving apparatus for use with a hot water system, the apparatus being sized and shaped for installation proximate one or more water outlet fixtures for delivery of heated water from the hot water system for use. The apparatus comprises an insulated reservoir having an inlet and an outlet to enable the reservoir to be installed in line with the flow of heated water from the hot water system to the one or more fixtures to store a quantity of heated water. Water that has cooled in the hot water pipe between the hot water system and the reservoir mixes with the stored heated water in the reservoir as water flows from the hot water system to the water outlet fixture.