The GREY FLOW PS SYSTEM is the only greywater system on the market specifically designed for new construction at the building stage. By installing our STAGE 1 BUILDERS KIT you now have a (GREYWATER IRRIGATION READY HOME). STAGE 1 is installed by the plumber at the pre-lay stage. STAGE 1 can accommodate a greywater pipe depth & is ideal for tight, narrow job sites. STAGE 1 comes 1.5m tall because not all homes greywater pipe is at the same depth. The extra pipe that sticks up out of the ground is cut off to the elevation of your choice. This way you are never trying to make your flat work or finished elevations work to the system, instead the system adjusts to you.