Try a wall mounted sink basin and a toilet that doesn't have an elongated bowl. These will save space.

I'm just commenting so as to give this a bump, hopefully someone with better ideas will come along :) I understand why the side door has gone in and it's also a bit of a trek with shopping. Could you not however move the new porch door and coats to the opposite side (maybe make the porch very slightly deeper) and then you could have a door straight into the kitchen from the hall? The seating area doesn't work for me, it looks much too close to the kitchen to be safe. I would also think about the safety angle of the hob on the peninsula with seating behind, splashes go a long way. By eye it looks as if you could have an island, maybe move the hob along and have seating in an L shape. I then might have a loveseat or something against the utility wall although you could just add a banquette/DiNing sofa to the table so you get a comfy seat with garden views (I assume you're not having a tv so just want the view?) do you have a plan with exact dimensions and maybe someone could mock something up? I don't think the kitchen is small in any case :) i might also think about the bathroom layout with the vanity in front of the window re having a mirror

Wow thank you everyone for all your suggestions and help with this. So many good ideas and things to think about! @tim-baker921 thanks for pointing out that a corner WC could work with the initial design put forward by us... it's a good to hear that although we do now agree with the advice from on here that it is better not to reposition a WC too far away from the soil pipe, so we have gone off that design a little. @Phil West, we totally get what you said about the finish being more important than the quantity of amenities. And we agree that it's things like nice lighting and attractive niches that'll make the difference to the overall result. I have no doubt that when the time comes I'll be scouring houzz and Pinterest for ideas and inspiration! @Wendy, thanks for your suggestion, we are open to the idea of a smaller bath if it would make for a better layout work but I have been trying to visualise what you mean... is the position of the "2m" high wall that you describe meant to be cutting straight through the main window? Surely I have got it wrong! I'm wondering if you meant shower on the left (external wall) as suggested by Jonathan? I liked Jonathan's suggested layout but the difficulty is that the wall between the small window and the far left corner is only 69 cm. In addition, the soil pipe is in the far left corner too so it would need boxing in, thus reducing the available floor space ifor a shower in that corner, My husband says he could box the soil pipe in and possibly create a useful ledge within the shower... and I have been thinking perhaps we could gain a bit of extra shoulder space by using a bow shaped/ curved door so perhaps all is not lost! So anyway folks, as you can see we are still dithering about whether we can have a separate shower or shower over the bath. We are still leaning towards the latter. If anyone has any thoughts on this they would be most welcome :)

You would probably need a worksurface next to the washer dryer to place items down as you remove them unless its straight into the laundry basket? Is that sink a sink as such or a washbasin? I'm sure it could work well. They do it all over Europe. Its a much better way of collecting laundry. Think about a laundry basket too. It might be very handy to have it in there next to the washer dryer. Could you provide some dimensions please to give a better idea of the space available?