Annual Water Use Study Report 2002-2003

April 16, 2009


All living things depend on water to survive. It is an essential and scarce resource, but one that too few people use responsibly. Australians live on the driest inhabited continent on earth, yet are the greatest consumers of water worldwide. In 2002, the national average water use in a four-person household was 1250-1400L a day –
equivalent to 250 to 280 buckets of water consumed per household per day – and this is predicted to increase.

The Queensland Government’s Towards Healthy and Sustainable Housing Research Project in Rockhampton is demonstrating and testing ways that water is being conserved in Research House.

The Research House project involved the design and construction of a family home incorporating the principles of the Department of Housing’s Smart Housing Initiative. A Smart House is one that incorporates the elements of:

Social Sustainability: A Smart House has been designed with people in mind. It is safe, secure and universally designed

Environmental Sustainability: A Smart House is resource efficient in water, waste and energy

Economic Sustainability: A Smart House is costefficient over time.

For further information about Smart Housing please refer to Appendix A or visit

Hot Water

The amount of hot water used depends on the duration of the shower, the flow rate of the water-saving showerhead or the quantity of water in the bath, the type of water heater installed and as does the pattern of use. Research House tenants’ household with the heat pump hot water system (Quantum) used an average of around 129L per day. By comparison a typical Brisbane household with a 315L off-peak electric storage system used an average of around 140L a day. Accordingly, Research House has achieved annual hot water saving of around 4015L or 8.0% less than the conventional electric storage system. The shower and bath area alone can realise total water (hot and cold) savings of at least 139L a day or 50,700 litres over a year.

A higher efficient (litres/kilowatt hour) hot water system, heats a larger volume of water (litres) for the equivalent units of energy consumed (kWh). The quicker recovery period and the efficient conduction of heat into the stored water for the heat pump water heater (Quantum) means the stored hot water stays at a higher temperature over a longer period, with the benefit that less hot water is used in Research House.

Water Use Data and Findings
Over the year, the total average daily water consumption for Research House was 1150L made up of 49% for indoor use and 51% for gardens, lawns and other outdoor use.

The dishwasher uses approximately 29L and the clothes washer uses 43L of water per day respectively, which is approximately 7% of the total water usage of Research House [12 (figure 2)].

The wet areas such as the shower and bathrooms used a total daily average of 211L that equates to approximately 18% of household water consumption. Shower and bath usage has been combined in line with the Brisbane data. The toilets use an average of 116L a day, which is approximately 10% of total household water consumption.

Of the total water consumption for the year, 14% was used in cooking, cleaning and drinking which includes the Zip hydrotap (instant boiling and chilled filtered water dispenser), which the tenants usage averaged 9L a day.

The hot water average daily use in Research House for the year was 129L a day or 11% of the total water use.

The outdoor water usage was initially very high in the first two months (October & November 2002) due to the fitting of incorrect sprinklers with huge quantities of water being wasted through over-watering of the gardens and lawns. Installation and calibration of the correct low flow sprinkler heads provided a more efficient watering system. Even with this intervention outside water use still accounts for a substantial proportion of the households total water use – 588L/day (51%). []


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