The importance of water recycle is a primary argument all over the world, especially in consequence of the increasing water shortage. In Europe the daily household use per person is calculated from 120 up to 350 litres. The water cost increasing from 2000 onwards has clearly reduced the per-capita consumption. Whereas the cost of the water bill is currently still growing, it is expected a reduction of per-capita consumption, which could be set around 150 litre throughout Europe. EU legislation sets parameters for the discharge, all European countries should ensure the attainment and maintenance of these objectives, which, thanks to the increase in the water bill, can be pursued. Usually half of water volume used in houses does not to be potable, as for toilet flushing, houses cleaning, car wash, watering garden. Besides reducing the use, recycling systems can be adopted to reduce consumption. This can be achieved through the project of dual water networks, served by a grey water recycling plant, rain water recycling plant or black water recycling plant.