Hi Katie. I've just finished a reno in a bathroom approximately this size. it looks like the toilet is currently on an exterior wall. if this is the case it can be costly - or not possible to relocate the plumbing. Yes, I know cisterns can be installed in the wall. My plumbers are wary of these ....try fixing a fault without cutting a hole - or holes - in the wall! If you are restricted to the outside wall, I would install a sliding door (gives you more space in the actual room). Leaving the bath and shower where they are saves $$$. if you move the toilet further to the left and install a wall-hung vanity under the window, you could also add a 'half-wall' to the toilet area for privacy. (Wall-hung vanities open the room up. This plan would give you great space on the left hand wall for storage and/or laundry hampers, You could of course switch the bath to the opposite wall, and move the toilet to the current bath area. Moving the door to the right AND installing a slider, would allow this. (BTW I just installed a 1700 bath - 1500's are available too.) Hope this is not too unclear! Enjoy the process!.

Based on the plans you provided I would go with number 2 (top row - right) with everything on the right hand side, so you walk in the door and the room looks spacious and you are not looking directly at a toilet from your hallway. All the plumbing runs along one wall and that is always the cheapest option and you can have a heated towel rail or similar running along the wall next to the entry. If it is possible I would rehang the door so it opens to the right not the left and then I would swap the toilet and basin so the toilet is tucked behind the door (for a little more privacy) and the vanities will be next to the shower. Good Luck.

my suggestion includes a free standing or set in bath up to 1800 x 800 (the "overhang" would be a feature not a restriction) and any gap between the set in bath and the walls can be filled in with an extended tiled ledge, twin 900 x 500 or an 1800 wide double vanity with matching mirrored wall cabinet, a 1200 x 800 shower and the toilet tucked behind the door with a generous window over the bath, subject to view and privacy, a window down as low as the bath with plantation shutters for privacy could work very well in the alcove

there isn't enough space for any complex arrangements and a simple neat small bathroom and separate laundry will be so much easier to use if you make sure that all the fixtures are sized to suit ie 90cm wide vanities for bath and ensuite with in wall mirror doored wall cabinets will enhance the feeling of spaciousness and hinged doors are great for extra towel rails and coat hooks as sliding doors would need need thicker walls, restrict attachment of towel rails and interrupt electrical wiring and plumbing and how low is the bulk head??? shower should fit OK as long as the bulk head is no lower than door height and even a bathtub with handheld shower is still better than a shared bathroom laundry open to the back door...best of luck