I like Option 2 honestly. Obviously you are finding it hard to visalize what the space will look like but honestly that is a huge space so I would recommend putting in the utility considering what you gain from it. You gain a space where you can block out the sound of the washing machine- who wants that sound when your eating dinner? Also washing is unsightly- do you wants piles of clothes in your nice brand spanking new kitchen? In terms of the corridor you are going to have lots of light coming through from the new extension. When you enter the front door and can see straight through to the garden spaces feel much bigger than they actually are anyway. Also who says it has to be boring. Have some fun wallpaper or colourful art hanging. Also if you want to make something more spacious use sliding doors for utility and wc. Less items infringing on corridor space. And lastly, the reception is purely personal preference based upon how your family function. Personally I prefer two rooms. Allows for more space to get away from the open plan area. Mini adults room and a kids room/study. Hope this helps

Thanks for the reply, don't think I'm quit at that stage yet though. Was more looking for general ideas on where cooking/dining areas could be located and how to fit in the utility and loo. Hoping that others who have done similar projects could share ideas on how to get the best layout for the space.

I second Johnathon's kitchen extending across the pantry. I'd consider leaving it as a straight run of kitchen units though. No return or peninsula. That would help with opening up the space. If it's a 2 bed flat the 3800mm (?) run should be enough if it's planned well. Especially with a induction hob and smaller sink and that lovely large pantry, you've got more enough space. Then you could add a longer but narrow table with one bench seat. Tuck that against the side wall with the bench under and you can use regular chairs around it (or another bench on the long side). Pull it out from the wall when you have guests over. The leftover space can be filled with a nice lounge area.

To get an island in your kitchen you will need 3.3m which leaves a living room that is only 1m wide which clearly not going to work- as it is I think the living room is narrow so offer an alternative