Why isn't it compulsory for all new homes to have rainwater tanks?

The costs and yields from a rainwater tank can vary significantly in Perth.

Our weather patterns can result in tanks being full at some times of the year and empty at other times, such as in summer and other periods of low rainfall. We support customers who choose to install a rainwater tank but don't believe that this cost should be introduced to all new homeowners. 

New houses are generally quite water efficient as building codes require the use of water efficient appliances, lot sizes are relatively small and waterwise planting and hardscaping are often used to reduce water use. For this reason, large scale installation of rainwater tanks remains an option for the future.