Determination of domestic flushing water consumption in Hong Kong

Purpose — To determine the domestic flushing water consumption for a building development. Design/methodology/approach — A statistic mathematical model is proposed and the model parameters are sampled with the Monte Carlo sampling technique. The frequency distribution of the parameters for Hong Kong is identified from the survey results of the water closet usage patterns in five typical residential building estates. In particular, the density function of the diurnal variations of occupant load and flushes per occupant, and the cistern volume of the water closets in 597 apartments are used to establish the model. Findings — The flushing water consumption of the residential developments in Hong Kong is determined and compared with the measurement result of typical residential buildings. Research limitations/implications — The model parameters are not exhaustive and are determined from surveys in Hong Kong, which perhaps limits the model's usefulness elsewhere. Practical implications — A useful source of reference in determining the domestic flushing water consumption of building developments for those involved in building design and management related to the flushing water systems of residential buildings. Originality/value — This paper proposes a statistical mathematical model of domestic flushing water consumption and presents a template to determine the required model parameters. The model offers practical help to professionals involved in planning, designing and managing the flushing water facilities for domestic buildings.