As a guide - the bigger the room - the bigger the furniture needs to be ! I have, for example , a pair of 8' ( four seater ) sofas in my lounge and the day I ordered them, three times they asked/checked I really had room for two of them, as they were the biggest sofas in the shop !! My lounge is about 6mx5m with 3m high vaulted ceiling - and the sofas actually look the right size, anything 'standard' would look too small in there !!!

Is the window just what we can see in the picture, ie it's high up and would be above the vanity mirror? If so, I wouldn't worry, I'd put in one large mirror with a beautiful frame, which matches the width of the plantation shutters, or, one which is narrower and then hang a beautiful pendant lights from the ceiling, either side of the mirror. I'd also go with a vanity which has legs on it. Maybe a "Hamptons" style

Your renovations are well underway, so after seeing the small floor plan and that the vanity is on an internal wall and you apparently still want the Shaving Cabinet. Having cavity brick walls I would get your brickie to remove a section of the brick wall so that the shaving cabinet can be recessed back into the cavity, this will overcome any concerns you have about bumping your head, this opening can then be patched along with other walls. I would take all of your photos and measurements to someone like Reece to pick a hand basin to fit,, I would also keep in mind that if say the width of the vanity is around 900 the shaving cabinet would match that width and you would end up with say 2 x 450 mirrored doors, which puts the mirror join in the middle and in your face when using the vanity. cheers

I'd ask the question from the opposite point of view . What will closing the lounge off achieve ? It may make it look dark , it may make it look pokey , you have Bed 5 the other side of the entry , and although that presumably won't be used much , I'd actually be more inclined to try and hide that door . If you are worried about a steady stream of people heading to the stairs or kitchen , disrupting the people in the lounge , then why would you put the lounge there in the first place ? Enjoy the space , or move the lounge would be my obvious observation .