Can't figure out your measurements--we need them in inches.

And anyway from the looks of it, you're not getting more square footage with the peninsula, you're getting less.

What is that room in the front next to the kitchen? And why a door from the hall to the kitchen?

Are you in the UK? My impression of homes there is that they all have a lot of doors in spots where a US home would have a cased opening. I chalk it up to cultural differences. I’m not a fan of brown sauce either, but 69 million people can’t all be wrong. 😂🇬🇧

You’re worried about creating a barrier island, but your island needn’t interrupt the flow of movement in the space, and as Diana points out, you’ll get a lot more worktop space with an island.

Here’s what I don’t love about the current plan, assuming I’m reading it correctly. You have a double sink (I prefer a large single bowl) staring into a wall. I don’t love island sinks, but I’d rather do dishes at the island than facing a wall. Will your refrigerator be in the utility room? If so, again, I’d rather clean veggies and prep at the island than have to walk over to the sink in its current location, so at least consider a prep sink in the island. Lastly, it looks as though you have no full height pantry storage although you have plenty of room for it.

I’d keep the island but plumb it. Whatever you decide to do I hope it turns out to be wonderful for you.

If that 1000 between the island and main part of the kitchen means centimeters, that is not enough space.

1000 milimeters is 39.3 inches. Folks will tell you that’s not enough room, even i will concede i’d like you to have at least 10 mm more in that aisle. You could make your island 10 mm smaller. But we don’t know where you live, or what building code is there. I imagine whoever drew your plans does.

Don't use a screen shot, use a jpeg and you need feet inches for everything. It's a USA site and yes, we are lazy and nobody wants to convert.