Can you add a skylight? That way you could have the bathroom along the external wall and the dressing room/WIR in the other half of the room. Is it worthwhile knocking a hole in the wall from the bedroom directly into the 2nd bed and then closing the doorway to the hall? That window is slap, bang in the middle of the room so unless you want to change/move the window I don't think you have much option than to run the rooms lengthways instead of across.

the shower room is about 2700 long and wet shower floor about 1500 so dry standing space should be about 1200 and towel rail about 2.5m away from the shower head so heated towel rail shouldn't be a problem ...the sliding glass door is meant to enclose all the moisture within the shower room and to be kept away from all the other rooms while still allowing light from the skylight to be shared with the adjoining rooms by retaining the slope in the existing ceilings and adding a ventilating skylight directly above the shower and adding fixed panes of glass in the wall between the shower space and the other small rooms and having just the 2200- 2400 tall partition behind the bed and between the ens and wiw...the wardrobes could still have the storage built up to 2400 and the dust can just stay where it lands and sparkle in all that lovely light...sadly, i have two perfectly sized Velux roof windows awaiting a new home but transport costs could far outweigh the cost of buying local but i've occasionaly seen them offered on Gumtree etc so start looking

This is my bedroom/ensuite set up. Overall our rectangle is 3960 x 8030. this concept with WIR first then ensuite may work. However your bedroom size may have to be reduced. The measurements of spaces are along the top of plan. Orientation would be the same as my plan, just entrance door/window position would change.

Are you refitting an existing apartment or is this a new build? Can windows and door be changed. Okl plan is heaps better but has diff windows to ensuite and wir. I would even say it is best if you can’t change windows. In heritage buildings they build walls into windows wir doesn’t have to have window. Good lighting and floor length mirror you can borrow lighting from ensuite with some glass between.