I like your extension. It's a wide open space with a logical layout. You have not explained what your needs are. Would you like to get a snug space out of this extension? There seems to be a lot of wasted space with huge walkthroughs which although airy and lovely to have might be better used for storage or for a part of it as a study/home office. Do you need a childrens play area? That sofa facing the island might be better as a second tv viewing area for example? There is a lot of dead space between the dining table and the kitchen. The dining setup might be better turned 90 degrees and placed alongside the island with the space used as a open games/tv viewing/ library (you could build a media unit along one of the walls)or entertaining space.

I want snug area with TV and need suggestions for more maximize use of space.

Is it already built then? Is this your furniture in the space and would you be open to changing it if necessary? What is the dimension from the island to the wall behind the sofa? I also need the width of your dining room and how many people you need to seat? It might be possible to build a banquette against the wall where the sofa is currently placed. I am not a big fan of them but they can look lovely and do save space.

That could be AI generated picture it’s hard to tell these days! I would consider swapping the dining table with the sofa and putting tv on the wall of the utility / toilet unless the tv is on the wall opposite island so the person cooking can watch it? I would consider if you really want double doors between your living room and middle room - great for having a party but you are losing a whole wall of storage on both sides.

Thanx for suggestions. We just start our extension which is 4.2× 5m. Yes this layout and picture is created by our architect. I would appreciate any changes in this layout. Dimension between island and wall behind sofa is 1.5 m. And dinning room width is 3 m.

If you haven't started yet I would move the island closer to the kitchen cabinets to make space for a dining table and chairs. What is that dimension? Most tables are about 700mm wide but you need to allow for chairs too which is why a banquette might suit you? I don't think 1.5m is enough for a comfortable dining table arrangement which is probably why the architect placed a sofa there.

Is the dimension you've said of 1.5m from sofa wall to back of island correct? It looks like the width is 4.83 less 0.6 units, 1m gap, 0.9 island leaving 2.33, If so a banquette (but with a pedestal table that can be pushed back against the banquette when not in use) may just be do’able but it is pretty tight with island stools

i agree with Chloe re doors to the living room and would think of tv sound travelling between the 2 rooms

Have you thought about blocking the doors and putting the utility in the 1st part of the dining room and rotating the loo 90 degrees? Would also five you a view of the back garden from front door

Personally I'd skip the stools as the table would be close enough to use daily for all meals.