The plumbing connections must come out of the wall behind the back section. It is important to determine the exact position of the back section so that the pipes can be made to come out in the 11cm gap, measured across the centerline of the back section and in an area between Y1 (made up of the height K of the base unit from the floor, + 16cm corresponding to the low bottom back panel + about 6cm for safety’s sake) and Y2 (equal to Y1 + 24cm if the base unit is 60 cm deep, +36cm if the base unit is 72 cm deep). The drain pipe must be installed at the bottom.