thank you for your comment. we are looking at using the interior wall, opposite the sink, for ceiling height cupboards utilising the wall cavities so as not to crowd the thoroughfare. I will keep a look out for replacement wooden windows. i would like to move them to the left so as to create more space in the corner area for hopefully a fridge? what to do with the fridge?

Personally, it's better to have a wall between the bathroom and the toilet so no one gets walked in on. Definitely a good idea to keep the bath in case of reselling, although are you planning on going anywhere? If not, get rid of the bath and get a bigger shower I think.

We have a 900x900 shower and it's plenty big enough. Neither of your proposed layouts looks that great, to be perfectly honest, sorry! In the first layout, you could improve it quite a lot by swapping the toilet and vanity (centre the toilet under the window on the bottom right of the picture if possible), and having the shower door on the other wall (beside the door). Then, you could have a towel rail on the wall beside the door (i.e. behind the door when it's open), which would be accessible from the shower but hidden when the door was open. An 800x1200 shower might be a good size for your space. You'd have to choose a toilet that doesn't protrude too far, plus a narrow vanity. With that layout, you could have a long but narrow wall-hung vanity, with a big mirror covering the wall between the windows, which would make the room feel bigger and would give a good amount of storage. Also, you may find this helpful: http://www.houseplanshelper.com/small-bathroom-floor-plans.html?utm_content=buffer4aa20&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

I love three in ones because if one bulb explodes, you've usually got a fair few backups before you have to completely fix the bulb (but that's just the laziness in me coming out). In my opinion, I don't think you need a demisting mirror because that's what the fan is for in the three in one.