For those still reading this thread. We just recently completed a bathroom reno in almost identical sized space though turned the other way. A lot of reflection in the photos sorry but there is a lot of glass and mirror. A cavity slider, while an added big expense, made the whole thing possible. To create the space I used the adjoining separate toilet room for the 1200 x 900 shower and shallow tall cabinet on the left and gained a closet in the hall outside with the rest of that corner. I also recessed the towel rail which helped give room to the shower entrance and not stick out in front of the loo. Wall hung vanity and toilet. Porcelain wood planks on floor with underfloor heating and also used in shower base. Excuse the towels, they are not my normal ones ! It was a big decision about joining the rooms and whether to keep the bath / shower but I think it paid off. There is just the two of us and it's a real pleasure to use and no longer feels like "standing room only"

hi we have about six months ago now, re done our bath room , similar size to yours, and , i can take some photos and email them to you , we have maximised space, and walls , put in a white stone bath under the window , it is a metre in width , with a cool water spout coming off the centre under the window we pu t afalse ledge in to sit , candles etc on , , we tiles floor to ceiling, off white , wall mirror cabnit with three mirrors , inset into the wall so its only sits out a we bit from the wall tiles , floating bath room vanity , so that it makes the floor space look bigger , . matching stone square basin sits ontop of the vanity to one side so plenty of room to sit all your bath room stuff when need be , seperate shower all tiled as well , with inset , shelves for shampoo etc, also , when you open the bath room door and walk in when you close the bath room door behind it next to the shower is a very narrow floor to ceiling shelvec for towels, now the hole is there we jaust havent got the shelves put in yet. , we gt loads of comments as the bth room dosent look small evn though it is , , most expensive item the sqwat extra wide stone bath , made to order basin / tap ware and shower spray thing ,oh and the white stone vanity which we had made to order as well , due to the sizing .

your alternate bathroom with the big shower and the old doorway between toilet and laundry should be able to squeeze in a shallow linen or storage cupboard (access from laundry and/or bathroom and built in all around based on the stated dimensions the bathroom appears smaller than in the photos (and/or the walls are thicker or the stated real estate photo measurements are wrong) so make sure you confirm accurate dimensions and consult a plumber before making any plans

i would probably try for at least 90cm but depends on the size and shape of the room, location of doors and windows and size and shape of other fixtures..can you post a plan of the room?