I think you can definitely do this, provided you can move your door which you said you can. I have an ensuite at the side of my main bedroom - it's small but perfectly adequate. I measured it and including all external walls the ensuite takes up 1.4 x 3.05m space (my bedroom including the ensuite is 4.7m long so shorter than yours.). My room is wider (3.9m) so I can have a wardrobe along the wall where your door is and the bed on the opposite wall. But for you, I'd keep your bed where it is and look at putting your bed in a 'wardrobe wall'. you have the depth (1000mm) before the window starts and I think 3.3 m is wide enough ... ~800mm robe either side of bed. See pics below for what I mean. Only you will know if this is too squeezy but an ensuite can make so much difference to your lifestyle, I think it could be worth it!

Hi Paul In apartments, the killer for layout changes are always drains, then water supply, then load bearing walls. Before you consider doing any changes to the layout, I would advise you to locate the drains (pics would be good) as they will likely restrict you. The drains are important for obvious reasons but also important is the fall (ie downward slope) of any drain you wish to install in a separate location. It means you have to take into account more height the further away from the existing drain you go. It is likely that your existing laundry trough/basin has a drain going down to the floor, and this is going to interfere with the proposed ensuite entry location. Ditto if it is going into the wall. The big one is the new shower. It will need to have a 50mm waste (drain) in the centre of where your washing machine now is.... and the question is where is it going to go.... I would suggest swapping the vanity and shower over to access the existing trough waste if it is large enough. In a lot of these older apartment buildings, the waste sizes are down at 38mm, which is not going to drain fast enough for a shower. If your existing waste is that size, you will need to have a hob to the shower as it will fill up, and you will also need to check health regs to see if it is allowed in your state. To get the drain for the new ensuite vanity and new laundrette sorted, I would punch through the new kitchen wall and run drainage along the wall behind the new cupboards and around to the existing kitchen sink waste. This will give you plenty of fall and a place to hide the pipes. For the new basin to the existing, you will need to see if you can get it around to the existing basin waste in the bathroom adjacent by running it around and under the bath. Cheers

We have the same layout as you in our 90s spec built home. We have Bunnings type cavity sliders so I imagine ours are about as cheap as you can get. They are awful - they are noisy when they slide so if one of us gets up in the night for the bathroom, we have to open the door in slow motion so as not to wake the other one up! We have them on our other wet rooms through the house and I find them not too bad acoustically but they don't screen anything in the ensuite. I would not recommend them at all. As for whether to have 1 or 2 doors, the only time I close the WIR door is when I am at my wits end haha! It's a great space for a private phone conversation but I really couldn't be bothered closing the door any other time

If you can swap the toilet to the outside wall in en-suite that may allow a slightly bigger vanity. With bed 3 if that will be a study you could take space for master wardrobe. I note you really do need the extra master robe. If you are happy with only one bedroom on that level, maybe change the bathroom up their to a powder room and enlarge the en-suite.