Water consumption benchmarks for residential buildings in Hong Kong

Fresh water consumption is a key issue for sustainable building designs as well as plumbing and drainage systems. Various benchmarks of water consumption were developed for the indication and promotion of building sustainability. Unfortunately, simple normalization of a single parameter might not be representative for a probable domestic water consumption benchmark, while a complicated benchmarking model could impose difficulties in general adaptation. In this study, a simple domestic water consumption benchmark for building sustainability using a five-star rating system was proposed. With the system, the least sustainable households, i.e. the top 10% of the survey samples in water consumption, were awarded the lowest sustainability rating ‘1 star’, and the most sustainable households (i.e. the bottom 10%) were awarded the highest rating ‘5 stars’. This simple model could be useful for identifying the extreme cases of water consumption and promoting the policy on sustainable building designs and operations without inclusive measurements.