We decided against it at the time.
For a short period, we also considered planning the whole thing in the dressing room (11 sqm). But the disadvantages outweigh the advantages, such as additional water pipes, wastewater pipes, tiles, sink, space requirements, etc. We already have all of this in the WC anyway, and the additional costs for the branching are marginal.
We have our washing machine and dryer upstairs in the WC (8 sqm). The room is basically divided into two parts – the left side has a sink and toilet, the right side is hidden by a sliding door and contains the washing machine, dryer, laundry basket, and shelving system. We are currently equipping the room with the appliances!
Our dressing room now has a nice parquet floor with a wardrobe system, and the 11 sqm is just enough for us (better for my wife).