I would do three things: Firstly get a second opinion from another builder as clearly these flats can be altered so this one builders assessment that it can’t be done seems wrong. I would be very surprised if it is not possible to put a big opening in this wall if not take it out. Secondly I would introduce yourself to neighbours- particularly the people above- You might notice their layout and changes they made- it might be that your kitchen wall is not holding anything up. Thirdly I would contact the freeholders about your intended alterations as they may have requirements or advice that makes your decision making process easier. Best of luck

I’m struggling to understand the layout. To me the dining area is oversized and it you could have the kitchen in the dining room, knock the two bedrooms together to make a living room all of your living accommodation would be on the same level. Is there a possibility of using a different entrance than through the living room (which seems like if could be a nice bedroom)

i would: move kitchen to reception room, but explore other options in terms of layout of this space and where the kitchen is within it (there is a fireplace indicated on the wall you want to knock down so likely that wall is structural). knock through toilet and bathroom to make one larger space, but as last comment, think about where the door is carefully the storage area within bathroom area - could that be accessed from the hallway? a good place for jackets and shoes (and you will find having a large storage area invaluable for suitcases, sports gear, hoovers etc) convert the existing kitchen into your study - you can always have this as multi- functional by putting a sofa bed in it also so it can be a space for occaisional guests shorten the very long corridor, so that you can join the last bedroom to the reception room and form an L shaped living space. you could keep a screen or have double doors between reception and the ex-bedroom space, so making it more of a snug...and again this could be multi functional if you had a sofa bed in it....close it off from the reception room you can have 2 sets of guests staying without giving up your own room at all. when you are preparing to sell in the future and you still want to sell it as a 3 bed (check with an estate agent first, having 3 beds and a small reception space with a kitchen somewhere in it doesn’t automatically mean more money), all you would need to do is close off this ex-bedroom space from the reception area by reinstalling a stud wall and put a door through at the end of the hall. this wouldn’t be a massive job to do and means you can live in the space the way you want to while you are there

I like Wumi’s design as well and can see why you’d want to have the front room as a living space, it’s lovely! A slightly cheaper/easier option would be to keep the bathroom where it is as that looks fairly new? Are you remodelling before you move in? Do you have the budget to do so? How crucial is the 2nd bedroom at this stage? I think living in and doing it room by room would be difficult but slightly easier if you didn’t need the 2nd bed immediately