The windows will run the entire width of the room so 2700 w but starting at around 1700 off the ground.. Floor and walls will be tiled and architrave will be timber. Window frames are UPVC.

@AAB That Ikea one looks like it has good dimensions from above, but I think you'd find 20cm too shallow to double as a useful laundry tub. If you could find one that was twice that depth… I did encounter such a sink in a long-stay apartment hotel I stayed in recently. The bathroom was fitted out with a combined washer-dryer unit and the "basin" – while styled aesthetically like a bathroom basin and oval in shape as well as rounded in cross-section – was really big. You could have washed a large baby in it! So clearly that kind of thing is available. It did require a fairly deep vanity to mount it in, but that was there to accommodate the depth of the washer-dryer anyway. The only thing with a deep vanity is you absolutely need to mount the mirror on a cabinet to bring it forward, not directly on the wall. If you don't do that anyone who is short and/or short-sighted has a hard time using the mirror for practical purposes such as shaving, inserting contact lenses, or applying makeup. (Yes, I discovered this during my hotel stay too!)

@oklouise thanks for measurement suggestions, good starting point with so many choices available. About the bath, we thought just a freestanding, or back to wall bath, would take less space compared to drop in bath. But it something worth considering with the suggested layout. Also, the bathroom entry door would be sliding cavity if that helps. @differentways thanks for a suggestion that we haven't really thought about. We have considered a smaller Japanese style deep bath, but obviously this would not be practical for kids. Just to make sure I understand your concept, you are suggesting a purpose built bath which will be about 2570mm (including the ledge), husband thinks this is very generous :). My husband and I can't find a photo of something similar, do you have a link? Are you suggesting the sides of the bath to be a lower height compared to standard bath? I like the idea of a ledge, would definitely make bathing kids easier. About the position of the ensuite, do you mean placing it outside the bedroom area so it can be accessed by others? We have discussed this, still part of ongoing discussion. If need to we just have to move the bedroom entrance door. I have attached a google earth view.

@dreamer I don't have measurements as we're not in the house yet... but attached is a picture of the bathroom. House is on concrete slab and brick veneer, so I imagine a bit more work would be required to remove and fill in said window? @Gianna Bruschi I might just suck it up and live with the current layout and a little refresh. We are only in this property for 6 years. Too long for me to want to live with a green bathroom and not long enough to invest too much. That's where my dilemma is.