hand toilet 102 the right hand line branch 133 leads to the left hand toilet 101 and the upper line branch 134 leads to the wash basins in particular it can be provided for the line branch 134 to supply water to both wash basins 105 106 to this effect a trifurcation 140 is provided the first left hand branch of the line arrangement extends as a cold water supply from the fork 140 to the left hand wash basin 105 or to the fitting 120 of the left hand wash basin 105 the right hand branch also extends as a cold water supply to the right hand fitting 120 of the right hand wash basin 106 the middle branch runs through a heater 117 before forking into two further branches wherein the left hand branch leads to the first wash basin 105 and the right hand branch leads to the second wash basin 106 or to their fittings 120 it is possible for all the lines that extend from the right hand module half through the dividing wall 108 into the left hand module half to comprise an interface in or on the dividing wall so that the lines of the left hand module half can be connected in that location and can optionally be removed in this manner it is possible to create a monument whose left hand half can be erected or removed as required at the first bifurcation between the fresh water line 132 and the left hand and right hand branches 133 and 134 a control device 107 can be provided for example in the form of a two way valve or a three way valve this control device can control and regulate the maximum possible flow.