Hello,
Would you feel comfortable in an 80 x 80 shower or in a 175 x 75 bathtub?
It is hardly about how "Musketier" would "feel," but about your willingness to accept a small death; 2.76 x 2.76 m requires a willingness to compromise.
Since, as already mentioned, these are shell construction dimensions, in my opinion your only option is to move the door if you reject a sliding door. Then I arranged the layout of the objects so that it won’t feel too cramped; without that, it will hardly work, although ordering the bathtub below the BRF will still provide you with some shelf space. If I have estimated correctly, you should be able to separate both the toilet and the shower — here I would seriously consider a walk-in shower — by means of a privacy wall.
And yes, the drywall installer can definitely deliver exact dimensions; of course not to the millimeter ;)
Best regards from the Rhineland
