In some cases greywater recycling may be used as a means of reducing water consumption to achieve higher water efficiency performance levels.

Where greywater is to be used, follow these instructions to calculate the contribution from greywater (litres/person/day):


Where a communal greywater system is to be provided supplying more than one home, this table can be used in the same way however the figures entered need to be apportioned down to an individual dwelling basis.