Water used by buildings can be reduced by as much 30% by simply selecting water efficient plumbing fittings such as low water shower fittings, sensor controlled taps, dual flush toilet cisterns and waterless urinals. The Australian/ New Zealand Standard AS/NZS6400 Water efficient products – Rating and labelling standards have been developed to rate water using products. The Water Services Association of Australia website has a simple to use database of rated products.
A number of simple tips to reduce water use can be found at the Australian Save Water website. For the more technically minded, additional information can be found at the Australian Green Plumbers website.
Water use can also be reduced by collecting and filtering grey water from sinks and laundries, for use in toilets and irrigation. A number of proprietary domestic greywater recycling systems are available in New Zealand.
Rainwater harvesting is another simple way of reducing water use. Rainwater from some roofing materials can leave residues in the water supply and filtration will generally be required, if the water is to be used for drinking purposes.
Typically up to 40% of the energy used in an average Kiwi home is due to water heating. Hot water pipe work should always be insulated and where possible, grade A fully insulated hot water cylinders should be selected. EECA have compiled an excellent guide to home insulation.
Solar water heating can dramatically reduce energy use and low interest loans are often available to reduce the installation costs.
Isolated sinks are usually best served with instantaneous water heaters. This avoids heat lost by hot water sitting in long pipe runs.
When choosing pipe work insulation, select manufactured materials that are both CFC and HCFC free. Pipe lagging manufactured from recycled NZ wool scrap is also available.
PVC is considered by many environmental organisations to be a material which should be avoided, though this has been debated in recent years. There are a number of alternatives to PVC pipe work systems readily available in New Zealand.