I could see a fake floor platform constructed in front of the windows, going across the entire width of the flat. At the left side of the platform, put in a storage wall from the column back towards the flat door. Then, put a dining table or desk on the top of the platform. Build a slide out platform for the mattress. Although you are only looking at a small double, I would build the sliding platform sufficiently deep to hide a full sized bed (5-6 feet). If you had extra space, you could install hinged doors to access the storage space hidden under the far edge of the raised area. In the floor level area in front of the platform, use easily moved comfortable chairs that you could just push out of the way when you wanted to slide out the mattress. (Poang chairs from IKEA would be ideal). If you wanted an extra chair for company, consider a canvas sling chair like you would see at the beach which would store in a space scarcely more than an inch deep If you are looking for ideas, consider spending a few hours viewing boats at one of the London area marinas that sell canal boats. After looking at a few canal boats, your flat will look absolutely spacious! Just curious, if you wouldn't mind sharing, where is your flat and how much was the purchase price? (approx is fine)

What about something along theses lines ..... [ marketing note - this is an example of the sketch consult service OnePlan provide... We happily provided this for free to this Houzzer, on this occasion . Normal rates would be £35 p/h. Full CAD images available too, at either an hourly rate or fixed room rate. We are freelance concept planners, selling only design !]

Hello helbel71, A fireplace is lovely.. even if you only look at it! If it's leasehold you may have to obtain permission to do anything especially if it's to have it as a working fireplace.. It would have been good to have negotiated this at the sale point.. However if you can go ahead and unblock the fireplace.. you need to be sure the structure is sound by making sure the lintel is in place and there aren't any obvious signs of struts holding the top of the opening.. You'd see these.. So once you have cut away the plasterboard.. usually you can tell where as it will sound hollow or not as you go. Looking inside with one's phone light or torch you should look up inside the breast facing outwards- there will be a line or brick or usually now concrete lintels are used.. Or you may see struts.. in which case get a builder to put in a new lintel and then you can decide what to do with it.. It may be that it's sound and all in place.. So you can just get to the point of deciding how to present it.. For me it's a swan basket and logs as authentic as possible... even if it wasn't ever lit... Some people might light a candle or twenty but at any rate I always suggest the swan.. Now the next thing is to decide.. Will this hinder you spatially if you open it up.. as you will not have that wall to use or sit things in front.. I also want to suggest situating bathroom where kitchen is and visa versa.. You could have a wet room style shower area with a tiny sink and a wall hung loo.. Plumbing would have to be moved and you'd need to be sure you could do that but - I have seen the smallest shower room in a studio that was about the size of a phone booth! It worked.. then there's more room for cooking and or living area. All depends on what you can do and what is permitted and what is important as for some the bathroom size you have currently might very well be non negotiable.. : ))

Put a sliding door on your kitchen instead of the existing one to gain more space. Extend the shower wall to the end to make the rooms bigger and steal the kitchen window. Use opaque windows in the top of the bathroom to steal light for the kitchen. I've done it in mine and it's amazing the light that comes through. Kitchen space approx 1800x1600 you can get 3 units across (3x600) by 2x600, 1x400 along the other wall in an L shape. You could always put a hatch in the kitchen into the lounge if fire regs allow it and space?! Build up with slimline wall units to the ceiling to maximise storage but also to retain your worktop space. Post before and after pics!!!! Good luck