I don't think I could cope with an open plan bathroom, I like wet areas to be totally separate, the steam entering the bedroom would be of concern and I would not want to even think about a toilet. We did not even like the idea of having the ensuite opening directly off the bedroom, instead have the dressing room opening off it with the ensuite opening off that. Having the dressing room between the ensuite and bedroom totally minimises noise. I find it far more convenient to walk from the shower directly to the dressing room to dress without even going into the bedroom.

Sounds fascinating but I can't see any photos yet. Maybe try to post again.

4 X 3.3m is a great sized space (bigger than our family bathroom, anyway!) I found the Reece bathroom planner a good starting point as you can gain a 3D view of the plan and it is fairly simple to use. We have decided to create a wet room sort of space at one end of our room (shower adjacent to bath with a single screen between shower and the rest of the room) so that the bath/wall behind bath can be a feature. Something like this photo or see my bathroom idea book

is the TV room to be included in the master suite, what are the measurements of the rooms and where is the third dormer??