Hi Kate, with respect, I'm not sure I agree but all families are different I guess. I don't think you need locks, a closed door and a knock are fine in our house. I am assuming there will be another door to the kitchen aswell. Having the toilet at the furthest point means the back door can be opened to release any "odours" quickly if necessary so personally I prefer that location. That passage is the main circulation way so Having an "empty wall" keeps the passage clear. I did put a double heated towel rail just outside the shower and assumed the hand towel rail would be part of the floating vanity with a shelf underneath for extra towels. As they are teenagers I think they"ll be fine to reach inside the recessed cabinets. The sinks need to be quite narrow due to the 400mm wall depth in this corner, by recessing the cabinets it gives you more "headroom" when you bend to the basin to shave/brush teeth/wash face etc. Ditto, because of the narrow depth, getting a closer look is no problem and teenagers still have great eyesight anyway (unlike us parents!) I am an interior designer and property stylist and played with a few different layouts but I think that this one (a combination of busybeelissa, LouieT and my ideas) is a good solution given the space limitations and the fact that it's trying to work for 4 teenagers.

I love those long floorboards/wood-look tiles and they are the feature so you wouldn't want something too busy on the walls... personally I would go with a larger format say 300x600 rectified edge white tile with a matt finish for the Hamptons look... what's your vanity?... a timber one would tie in nicely with the floors and all the white... very Hamptons :)

also will give illusion of a bigger bathroom if you use bigger tiles ..I used small ones on one wall as feature wall and larger ones on other walls ..

There is absolutely no rules. But given most people struggle to makedecisions on bathroom fittings in not sure why you would put yourself through the pain of having to double the selection options! I would suggest putting a moodboard together of all the finishes you like and then work out how to divide between two rooms. E.g. maybe keeping floor tiles the same but having different feature tiles (if that's your cup of tea) in each room.