Just a quick suggestion, if the plumbing works place the WC under the staircase. And place the door so it does not open towards the living or kitchen areas. Please also post some photos of the house as it looks from the outside.

i agree with most suggestions above. but dont remove your current rug because u can actually layer a faux fur rug over it. plus your rug has amazing rustic colours and u can use them as accents. maybe over time you may invest in new pillowcases/quilt covers complementing the colours of the rug..peach/mint/cream/ to name a few. may also add some mettalic cushions combo. you can always take them off if you want that summery feel in which switch to sweet pastels. a lot of pillows are important! lol! i'd get rid of the plant. the dressing table n side tables could be black (lacquer may be interesting)with gold knobs (think art deco). dressing table should be move to the side so you get more light and space near the window. maybe mirror can be placed against the window so ull also get natural light when you're admiring your reflection. ur room has an eclectic feel to it.. its great just needs some rearrangments thats all.

I love the tall units but you need to go straight to the ceiling to prevent dust and dirt settling on the top. I would put a row of small up and over cupboards along the very top as an option. Very handy for unsightly bulky items. I don't like the end open shelves by sink very dated but what you could do is a long double shelf all the way along the island with a wine racking either side for balance vertically. I think shelving each side of the sink would be better. You have a lot of cupboards but no deep drawers which are highly valued these days. Good selling point. I Like your colour suggestions... The little Greene paint company have a lovely grey so does farrow and ball. Where are you sourcing your Quartz and what flooring? Do your ovens have easy open shelf doors ..handy as they retract so don't get in the way as you take food out..Neff offer best ones. If you want a better balance of tall you could always do fridge freezer one side and pull out pantry on the other with racking. Then on sink side don't go all the way along the wall just have it as centred space so you can pull out larder doors. On your island you will need your bin as this'll be prep area? What is the room opposite tall cupboards? Need the island to look good from that side as that is what you will see. Hope of help. I'm embarking on the same thing and have spent hours and hours researching!

If I'm being honest, I'm really not sure on this layout. You have services on both sides of the extension, which even with my limited knowledge of building is expense that you could avoid. Do you need a laundry and a utility, or could you combine them.? Also I hate the idea of a toilet off the kitchen. The garage also looks small. Could you take out the door on the garage and make that the bathroom off your corridor, and make the corridor your utility. Then you have all the space free where the new bathroom and utility are. If you want more space for the utility and bathroom I would suggest bringing that wall in (make kitchen and dining narrower) and that would have the advantage of making your study wider. One other point is that leaving the study there with a window to the side will make the kitchen very dark.