Oh so many replies - thank you all!
To answer a few points, the current kitchen is fine, not my taste really but too small for me, I’d have to lose two cupboards for my fridge freezer and another one for a dishwater too.
I’m not changing the kitchen before knocking down the outbuilding, I’m knocking down the outbuildings and rebuilding a proper structure there that I want to open up into the kitchen. So will need a new kitchen afterwards regardless. The outbuildings need to come down sooner rather than later and I want to get as much building work done as possible before I move in. I considered living with the kitchen as is for a while first, but I’d end up buying appliances to fit in the small space that I wouldn’t want in the big space, so it seemed like a false economy.
To @parietal - The boiler cupboard is on the left. So from left to right, boiler cupboard, sink with window, larder unit, fridge freezer, door. Then worktop with window, then more worktop with hob and pan drawers, cooker housing, more worktop/drinks area, larder unit/appliance cupboard, then archway.
I’m having a dishwasher so won’t need to wash up that much, but I do a lot of baking so I thought the area underneath the big window would be nice for making bread and the like there rather than being blocked by the sink! I could in theory block the window where the sink is now, but I thought it might make the room look dark, with only one window at the far end. The view from that window is just onto my side return so not particularly scenic but does let in a lot of light (as hopefully the before picture shows!), though it could work as a seating area, not something I’d thought of!
These replies are so useful - I do like the design in the sense that it’s a lot of open worktop space, there’s lots of storage (I really want to avoid wall units), but there’s bound to be a way I can get all of those things with a slightly different layout. Lots of you are suggesting all the big units on the right hand side so I will try a kitchen design later with that as a starting point!