Sustainable design in housing

A semi-detached residence at Clovelly in Sydney, which received a Gold Medal in the 2004 Green Building Awards, shows the water-saving solutions which can be adopted in an individual renovation or new home building project to conserve valuable mains water supplies.

The Clovelly house was designed to meet best practice in architecture, urban design and environmental design.

A principal outcome in water saving is a 75% reduction in town water use.

This was achieved through selecting readily available concepts and products implemented by the architects Kennedy Associates Architects and environmental engineers ENVDS.

The Clovelly house has three compact rainwater tanks in the backyard which can store 9000 litres of rainwater collected from the roof.

The tanks are frequently filled by regular rainfall.

The tank storages provide the cold water for the bath, showers and hand basins as well as the swimming pool.

They are equipped with a Davey Rainbank controller which automatically switches the water source from the domestic mains to the rainwater stored in the tanks whenever a demand is created.

The controller automatically determines to use the rainwater first and then mains water only as a backup, or as the supply should there be no stored water available in the tanks.

Another water conservation initiative is that the grey water generated by the house is biologically treated in a tiered vertical planter established alongside one of the boundary fences.

The treated grey water is then used for the washing machine and the toilet flushing needs of the house.

"The water-saving solutions are complemented by a number of features, ranging from enhanced thermal performance, to extensive use of natural light with low wattage light fittings, solar water and pool heating and provision for solar power generation," says architect Simon Anderson.

"The use of renewable materials including sustainable timbers and the selection of low volatile organic compound paints and floor oils are additional features."

The Davey RainBank controller is achieving a rapidly growing installed base in both homes and institutional building projects where a tank water storage system traps rainfall and employs it for regular needs, including toilet flushing, garden watering and supplementing swimming pool supplies, by simply diverting the use away from the high value mains water supply.