I am planning a new shower room, where it will be difficult and expensive to run the shower drain downhill to an outside drain. As an alternative, I thought of running the drain slightly downhill from underneath the shower to underneath the washbasin, then back up through the floor to a pump mounted at floor level. The pump would then suck the water upwards into the existing washbasin outflow. The pump would be electrically connected to the shower controller, so that the pump activates when the shower is started (and the shower would be automatically shut off if the pump failed).
Is this a feasible way of doing things? Any other way?
(I also thought of mounting the pump close to the shower under the floorboards, so that it would push the water to the outflow rather than suck it, but there would then be the question of how to get at it for repair/maintenance).