Nice work oklouise. I was thinking the existing porch could be a walk in robe with the current front door being the entrance to the robe. Then reduce the double doors from existing entry to lounge to single and put a new doorway to the study inline with the master/study wall. that way you aren't removing external walls. Entry would then be through a new doorway where the lounge window facing the current porch. If the window is big enough then it might even be possible to use the existing lintil above the window and just remove the window and the bricks below which will save $$. I know you lose hallway but lots of houses (including mine) don't have hall ways per say but use floor coverings or furniture to create walkways around the lounge. I guess it all depends on how much $$ you want to spend in th end.

I’m set up in our sunny spare bedroom. Happy with my spot as I have views to the street and a desk to work from.

the top of a vanity could be 780 (approx desk or table top height is around 750) or as high as 900 which is average kitchen cabinet height but is it for tall people, short people or average sized people and, as the space under the vanity is not tall enough for anything but dust and lost pills why not make sure the tops of the sinks is no higher than 900 for comfortable height for most people and that would make the floor space 220, the counter top 760 and the top of the basins 900?

Where are you building, in order to understand climate, and which way is north on the plans, to address light and energy efficiency? The downstairs powder room shows a shower so it appears to be a bathroom however what purpose does it serve as there is no downstairs bedroom? I can't find the fourth bedroom either. There are things that appear inconsistent, for example a way oversize kitchen complex befitting huge parties but no entry, nowhere for guests to take off coats etc, the luxury of not only two WIRs but a "make up" room also for the master suite, but the ensuite has only a single basin vanity and the wc is not separate. What is the pupose of the nook? It doesn't look large enough for more than one person at a time so is it fulfilling a purpose for you? Why are there so many AC ducts upstairs and none downstairs? What is "organic" about it, apart from sales pitch? It looks overly generous in some aspects while impractical in others. There is something to be said in these times for trying to build 'right size' rather than continuing to build houses which are the largest in the world, but even if that doesn't concern you, why build a large house which reduces or omits valuable features which would be expected in a house that size?