In Ontario, potential contributions of solar domestic hot-water (SDHW) heating to air-emission mitigation have been identified. The provincial utility Ontario Hydro does not include solar heating in its current demand-side management plans because of the capital cost barrier. We present results of life-cycle cost analyses for installing a typical solar system in single-family dwellings in Toronto. For high hot-water load, the generated societal benefits make solar domestic hot-water heating an economically viable option.